En route to a dentist's appointment, Hannah Jacobs' mother realised her daughter hadn't had breakfast and asked if she wanted a hot chocolate at Costa Coffee. 

The 13-year-old was due to have a check-up before a tooth extraction and having braces fitted.

But within less than ten minutes of taking a first sip of her drink in the dentist's waiting room, Hannah was struggling to swallow. As her chest grew tight, her lips and mouth became swollen and itchy. 

Hannah's mother rushed her into a nearby chemist's for help, where she collapsed. She was pronounced dead in hospital less than two hours later. 

Her voice trembling, Abimbola Duyile recalls: 'At that moment, my whole world came crashing down.'

Earlier this month, a coroner ruled that Hannah's death was caused by an allergic reaction from sipping the hot chocolate that her mother had bought from Costa Coffee in Barking, East London, near their home.

Hannah had severe allergies, which she and her family were adept at dealing with. 

But Abimbola says, despite her request for soya milk to be used and instructions to the barista that her daughter was 'very allergic to dairy', Hannah was served cow's milk.

Now, in her first newspaper interview since her youngest daughter's death in February last year, Abimbola, known as Abi, recounts the devastating events of that day – and the 'missed opportunities' by healthcare professionals to save her daughter's life. 

They had, after all, been in both a dentist's and a chemist's with trained medical professionals during the allergic reaction.

'I still lay in bed and think, 'Oh my god, this has actually happened!' ' says Abi. 'Every day that I wake up and Hannah isn't here is painful. My life is painful.'

She takes long pauses between sentences as the tears come. 'I blame myself a lot. I carry guilt every day because my child is not here any more. But what can I do? I have to go on because I have another child to look after.'

For those with children with allergies, it's their worst fears realised. Shocking new data revealed last week that the number of people with allergies in the UK has doubled in the past decade.

Scientists don't yet know why, although theories include the decreasing exposure to germs, as well as changes in the Western diet, including a shift towards ultra-processed food.

Hannah first showed signs of allergies aged around 18 months, when Abi attempted to wean her off breast milk and on to dairy.

'She vomited after a tiny sip. At first I just thought she was being fussy but, after it happened a few times, I took her to the doctor's.'

Specialists diagnosed Hannah with several allergies – to wheat, eggs, fish, dairy and peanuts. The family managed her condition well, opting for 'complete avoidance' of allergens.

Abi, a single mother, washed pans three times before using them to cook for Hannah. She took a week's worth of packed lunches on holidays too.

The policy had proved successful: Hannah never suffered a severe allergic reaction before the one that killed her.

On one occasion she had suffered swollen lips after trying a prawn and, another time, broke out in hives – a raised, itchy rash – after accidentally touching raw egg.

Both times she took a small dose of antihistamine cetirizine and her symptoms vanished quickly. As she grew older, Hannah was more than capable of managing her condition. Aged four, she informed dinner ladies that she couldn't eat the fish lunch.

'If Hannah couldn't eat something, she had no problem telling you,' recalls Abi. 'She knew what she could eat and what she couldn't – and she was firm.

'It took a long time for her to feel confident and safe but, eventually, she had the few places that she knew she could trust.'

They consisted of McDonald's where 'she could only eat chips', some fried chicken chains, a local Turkish restaurant – and Costa Coffee. 

'She'd always felt the staff at Costa understood her allergies,' says Abi. 'And she'd always order the same thing: a soya hot chocolate with marshmallows.'

So Abi didn't think it would be harmful to buy it for her before the dental appointment.

Crucially, though, neither were carrying an EpiPen, a lifesaving auto-injector of adrenaline for when a reaction occurs. Hannah's school banned students from bringing medication on to the premises (in case they lost it). Instead, two EpiPens were kept in the nurses' office. Two spare EpiPens were kept at home.

Abi has agonised that she didn't bring an EpiPen with her that morning as she rushed to leave the house. 'Most nights I stay awake thinking maybe there is something I could have done differently,' she says, adding: 'Maybe carrying an EpiPen with me.'

She says she asked the Costa barista for two soy hot chocolates – one medium and with marshmallows, and one large and extra hot.

'I said, 'I am so sorry to be a pain but can you also clean this jug out?' [The barista] looked at me as if to say, 'Why are you being so bossy?' I apologised and said my daughter has a milk allergy.'

The inquest at East London Coroner's Court heard that Costa has a strict food allergy policy. Staff are trained to present customers with a book that lists the allergens in every product – by pointing to the relevant ingredients, customers can make staff (particularly those whose English isn't of a high standard) aware of their needs. 

But the allergy book was not presented to Abi on the day of Hannah's death. The inquest also heard evidence from Costa employees about their online training on allergens, including from one who said they failed the quiz 20 times before passing.

'I trusted that I was getting the drinks that I asked for,' Abi says. 'I usually pay attention when they make the drinks, but on this day, for whatever reason, I wasn't.'

Mother and daughter carried their drinks to East Street Dental Practice, a few minutes' walk away. Hannah took three sips of the hot chocolate in the waiting room and got up to use the toilet.

'She texted me from the loo to say 'Mummy, that's not soya',' says Abi. I was fuming. I thought, you are joking.'

When they were called to the dentist's chair moments later, Hannah was spitting excess saliva 'all over the floor' – an early warning sign of anaphylaxis, a life-threatening allergic reaction.

'I told the dentist that Hannah was having an allergic reaction and we'd have to come back,' says Abi. 'They didn't offer me any help, but asked if I had medication on me.'

 Guidance by the Resuscitation Council UK says all dentists must have EpiPens on site. The inquest heard that the dental practice had EpiPens on the premises. Had one been administered, Hannah would have likely survived.

Abi and Hannah 'ran' across the road to DayNight pharmacy in search of cetirizine, which 'had always worked before'.

'Hannah said she had chest pain and I begged her to calm down,' says Abi, who believed Hannah's anxiety was making her symptoms worse. Shortly after swallowing the antihistamine pill, Hannah collapsed. Abi 'screamed' for an EpiPen.

According to guidance from NHS England, all pharmacies offering the annual flu jab must have adrenaline in supply, in case of an allergic reaction to the vaccination.

However, this often comes in the form of a vial, which takes around five minutes to administer.

The inquest heard that pharmacist Santokh Kahlon injected Hannah with an EpiPen that contained a junior dose of adrenaline – roughly a third of the necessary amount for a teenager. 

He told staff to look around to see if there were any more EpiPens but none could be found. 

Mr Kahlon 'did consider' using the correct dose of adrenaline from a vial. 'It would have taken me five minutes to prepare and inject. In the circumstances, there was a call to action, the child was critical, I couldn't wait,' he told the coroner's court.

Abi says the moment Hannah collapsed, 'everything went blank'. 'I thought, no, no this can't be happening. My child cannot die.'

A customer perfomed cardiopulmonary resuscitation on Hannah. Within ten minutes paramedics arrived with a defibrillator, at which point Abi knew 'that was it'.

'I work in a care home. I know what that is used for, I knew her heart had stopped.'

Paramedics tried to revive Hannah for over an hour, before taking her to nearby Newham Hospital. But about 15 minutes after she arrived, she was pronounced dead. Assistant coroner Dr Shirley Radcliffe concluded the 'root cause' of Hannah's death were 'failures' by Costa staff to 'follow the processes in place to discuss allergies' and communicate with Abi.

The two Costa servers who gave evidence did so with the help of interpreters, as English is not their first language.

'I don't know if it's a language barrier, or if the staff just couldn't be bothered,' says Abi.

'If she [the barista] brought out the allergy book, we wouldn't be in this position.

'Why didn't the pharmacist have a spare EpiPen? Maybe next time he will, and he'll save a life.'

Mr Kahlon told the court that a nationwide shortage of EpiPens meant the correct dose was 'out of stock'. NHS data shows that EpiPens have been in short supply since 2018.

Hannah's case is the latest in a series of shocking allergy deaths, like that of 15-year-old Natasha Ednan-Laperouse, who suffered a fatal allergic reaction after eating a Pret A Manger baguette containing sesame seeds.

Her death led to the introduction of Natasha's Law, which makes allergy information a requirement for food pre-packed for direct sale.

Abi and Natasha's parents are now working together to call for a government allergy tsar to police allergy safety and awareness in food businesses and beyond. Abi also wants Natasha's Law to be extended to drinks.

Natasha's mother Tanya, who co-founded the Natasha Allergy Research Foundation, says: 'It's become clear that, in all areas of society, people with allergies fall through the gaps.

'We need someone in government who can sit and listen to those affected, identify the problems . . . to make life safer for the growing number of people with allergic disease.'

A representative from Costa Coffee promised to issue a formal apology for its part in Hannah's death, according to some reports. Yet Hannah's family are still waiting. Abi says: 'What will an apology achieve anyway? It's not going to bring my child back.'

The coffee chain said: 'The loss of Hannah is a tragedy, and our heartfelt thoughts remain with her family and friends.

'We have strict allergy training and procedures in place to help to minimise the risk to those customers who suffer from allergens. However, we agree with the coroner's conclusion that our allergen process was not followed that day at our franchise partner store. We continue to review what more we can do when training team members to help to minimise the risk to those customers who have allergies and provide clear communication.'

Today, Abi and her elder daughter Abigail, 17, are 'just getting through to the next day'.

Abigail is adjusting to life without her 'best friend'.

'It's the quiet that I hate the most,' says Abi. 'I like noise in my house, and Hannah brought that out in everybody. Without her . . . it's like a ghost town.

'Hannah was a bright child, funny, full of life. She loved Christmas and her birthdays. She would have been an amazing adult.'