Vivian Jenna Wilson, the transgender daughter of Elon Musk, said Thursday in her first public interview that he was an absent father who was cruel to her as a child for being queer and feminine.

Wilson, 20, in an exclusive interview with NBC News, responded to comments that Musk made Monday about her and her transgender identity. On social media and in an interview posted online, Musk said she was "not a girl" and was figuratively "dead," and he alleged that he had been "tricked" into authorizing trans-related medical treatment for Wilson when she was 16. 

Wilson said that Musk had not been tricked and that, after initially hesitating, he knew what he was doing when he agreed to her treatment, which required consent from her parents.

Musk's recent statements crossed a line, she said. 

"I think he was under the assumption that I wasn't going to say anything and I would just let this go, unchallenged," Wilson said in a phone interview. "Which I'm not going to do because if you're going to lie about me, like, blatantly to an audience of millions, I'm not just gonna let that slide." 

Wilson said that, for as long as she could remember, Musk has not been a supportive father. She said he was rarely present in her life, leaving Wilson and her siblings to be cared for by their mother or by nannies even though Musk had joint custody, and she said Musk berated her when he was present. 

"He was cold," she said. "He's very quick to anger. He is uncaring and narcissistic." 

Wilson said that, when she was a child, Musk would harass her for exhibiting feminine traits and would pressure her to appear more masculine, including by pushing her to deepen her voice as early as elementary school. 

"I was in fourth grade. We went on this road trip that I didn't know was actually just an advertisement for one of the cars — I don't remember which one — and he was constantly yelling at me viciously because my voice was too high," she said. "It was cruel." 

Musk did not respond to a request for comment.

Wilson and her twin brother were born to Musk's first wife, author Justine Musk. The couple divorced in 2008, and Wilson said her parents shared custody between their homes in the Los Angeles area. 

Musk, 53, is among the wealthiest people in the world through his stakes in Tesla, where he's CEO, and in SpaceX, which he founded. He's also become a significant political figure, having endorsed former President Donald Trump this month for another term in the White House. Musk has 12 children, including Wilson. 

Now a college student studying languages, Wilson has never granted an interview before and has largely stayed out of public view. She did, however, attract attention in 2022 when she sought court approval in California to change her name and, in the process, denounced her father. 

"I no longer live with or wish to be related to my biological father in any way, shape or form," she said in the court filing. 

She told NBC News that at the time, she was surprised by the media attention to the court filing, which she submitted when she was 18. She said in the interview that she stands by what she wrote, though she said she might have tried to be more eloquent if she had known the coverage it would receive. 

Wilson said that she hadn't spoken to Musk in about four years, and that she refused to be defined by him. 

"I would like to emphasize one thing: I am an adult. I am 20 years old. I am not a child," she said. "My life should be defined by my own choices." 

Musk threw a spotlight on Wilson on Monday by speaking about their relationship in a video interview with psychologist and conservative commentator Jordan Peterson streamed live on X, saying that he did not support Wilson's gender identity. 

"I lost my son, essentially," Musk said. He used Wilson's birth name, also known as a deadname for transgender people, and said that she was "dead, killed by the woke mind virus." 

And in a post on X Monday, Musk said that Wilson was "born gay and slightly autistic" and that, at age 4, she fit certain gay stereotypes such as loving musicals and using the exclamation "fabulous!" to describe certain clothing. Wilson told NBC News that those anecdotes are not true, though she said she did act stereotypically feminine in other ways as a child. 

Wilson also addressed Musk's recent comments in a series of posts Thursday on the social media app Threads. 

"He doesn't know what I was like as a child because he quite simply wasn't there," she wrote. "And in the little time that he was I was relentlessly harassed for my femininity and queerness."

"I've been reduced to a happy little stereotype," she continued. "I think that says alot about how he views queer people and children in general." 

In recent years, Musk has taken a hard-right turn into conservative politics and has been waging a campaign against transgender people and policies designed to support them. This month, he said he was pulling his businesses out of California to protest a new state law that bars schools from requiring that trans kids be outed to their parents.

On the social media app X, Musk has for years criticized transgender rights, including medical treatments for trans-identifying minors, and the use of pronouns if different from what would be used at birth. He has promoted anti-trans content and called for arresting people who provide trans care to minors. 

After Musk bought X, then known as Twitter, in 2022, he rolled back the app's protections for trans people including a ban on using deadnames. 

Musk told Peterson that Wilson's gender transition has been the motivation for his push into conservative politics. 

"I vowed to destroy the woke mind virus after that, and we're making some progress," he said. 

Wilson was also mentioned in a biography of Musk by author Walter Isaacson — a book that she told NBC News was inaccurate and unfair to her. The book refers to her politics as "radical Marxism," quoting Musk's sister-in-law Christiana Musk, but Wilson said she's not a Marxist, though she said she does oppose wealth inequality. The book also calls her by her middle name, Jenna. 

Wilson said that Isaacson never reached out to her directly ahead of publication. In a phone interview Thursday, Isaacson said that he had reached out to Wilson through family members. 

Christiana Musk did not immediately respond to requests for comment Thursday.

Wilson told NBC News that for years she had considered speaking out about Musk's behavior as a parent and as a person, but that she could no longer remain silent after his comments Monday. 

She said she had never received an explanation for why her father spent so little time with her and her siblings — behavior by him that she now views as strange. 

"He was there, I want to say, maybe 10% of the time. That's generous," she said. "He had half custody, and he fully was not there." 

"It was just a fact of life at the time, so I don't think I realized just how abnormal of an experience it was," she added.

Wilson said she came out twice in life: once as gay in eighth grade, and a second time as transgender when she was 16. She said she doesn't recall Musk's response the first time, and she wasn't present when Musk heard from others that she was transgender because by then the pandemic had started and she was living full-time with her mother. 

"She's very supportive. I love her a lot," Wilson said of her mom.

The pandemic was a chance to escape Musk's cruelty, she said. 

"When Covid hit, I was like, 'I'm not going over there,'" she said. "It was basically very lucky timing." 

Musk told Peterson in the interview that he had been "tricked" into signing documents authorizing transgender-related medical treatment for Wilson — an allegation that Wilson said isn't true. 

"I was essentially tricked into signing documents for one of my older boys," Musk said, using her birth name.

"This was before I had really any understanding of what was going on, and we had Covid going on," he said, adding that he was told that she might commit suicide.

Wilson said that, in 2020, when she was still a minor at 16, she wanted to start treatment for severe gender dysphoria but needed the consent of both parents under California law. She said her mother was supportive, but that Musk was initially not. She said she texted him about it for a while. 

"I was trying to do this for months, but he said I had to go meet with him in person," she said. "At that point, it was very clear that we both had a very distinct disdain for each other." 

When she eventually went and gave him the medical forms, she said, he read them at least twice, once with her and then again on his own, before signing them. 

"He was not by any means tricked. He knew the full side effects," she said. 

She said she took puberty blockers before switching to hormone-replacement therapy — treatments that she said were life-saving for her and other transgender people. 

"They save lives. Let's not get that twisted," she said. "They definitely allowed me to thrive." 

She said she believed that the requirements to obtain such treatments remain onerous, with teenagers pressured to say they're at extreme risk of self-harm before they'll be approved. She said she felt judged by Musk and Peterson, in the Monday interview, for not being at a high enough risk in their eyes. 

"I have been basically put into a point where, to a group of people, I have to basically prove whether or not I was suicidal or not to warrant medically transitioning," she said. "It's absolutely mind boggling."

— CNBC's Lora Kolodny contributed to this story