"People in the north don't know the truth about what is going on. They don't know about human rights [violations], or the suffering [in North Korea]. They live in a virtual prison," Lee Hyeonseo said at a help center for North Koreans.
She said she bribed an official to escape with her family but declined to give details, Sky News reported Friday.
Lee described the difficult path to South Korea, saying the usual method is to travel through China, then to Thailand, where defectors present themselves to the South Korean embassy and request asylum.
She also said punishment for defectors' families left behind lasts three generations. A married couple, their children and grandchildren are all imprisoned if a family member escapes.