Vietnamese Huong and an Indonesian woman, Siti Aisyah, were charged with killing Kim Jong Nam by smearing his face with VX poison at Kuala Lumpur's main airport in February 2017.
The two women claim they thought they were part of a reality TV prank which they had been rehearsing for weeks beforehand in various public places by smearing bystanders' faces to see their reaction.
Huong had been wearing a t-shirt with the word LOL emblazoned across it when Kim Jong Nam was attacked and gained instant notoriety across Asia after CCTV footage was shown across the world.
Siti Aisyah was released last month after prosecutors dropped all charges against her.
Siti Aisyah, centre, was accused with Doan Thi Huong of killing Kim Jong Nam (Image: Getty)
Huong's lawyer said she "had taken responsibility" for her actions by pleading guilty and after already serving two years in prison should be ready for release in May.
Four North Korean men escaped from Malaysia hours