"My parents told me I was picked up in a bathroom," she said.
It might sound peculiar, but Wu's is not an uncommon answer when it comes to the descriptions Chinese children hear around matters of sexual education.
But that situation is about to change.
In March, the first batch of sex educators for middle-school children in China was certified by the national government.
The training courses provide a variety of content, including information tailored for both children and adults, online videos for family education, and summer and winter campaigns for adolescents.
Among the topics covered are matters such as sexual consent, common questions about sexual intercourse and debates around real cases involving sexually transmitted diseases and prostitution.
But the courses also aim to highlight issues of human rights and sexuality, said Fang Gang, the program initiator and associate professor of psychology at Beijing Forestry University.
The power of safe sex
Fang described the training courses as "empowerment sexuality education," as they teach adolescents how to have sex safely and responsibly.
"Empowerment sexuality education aims to help teenagers make their own choice about sex, which is a key part of a person's personal growth. It's actually an education of life," he said.
Fang said the courses are also tailored to give different perspectives of gender equality, LGBT rights and feminism. "It's not only about the sexual knowledge. We are teaching values," he said.
As of May, more than 130 people had attended Fang's training courses, and more than 30 of them became certified.
Courses entail seven lessons with Fang in Beijing and Zhengzhou, in central China, where participants give their own lectures on sex education for Fang to examine and improve. In addition, they complete more than 52 hour-long lessons online.
Limited knowledge before
Until recently, there had been very little, if any, sex education for young people in China, apart from the basics on sexual reproduction learned in biology textbooks.
The lack of information on issues around sex has left many Chinese teenagers dangerously in the dark.
For example, young people are a growing concern for HIV rates in the country; although national rates are very low -- under 0.1% -- an estimated 14.7% of new infections
in 2015 were among people 15 to 24. The year-on-year growth rate of new HIV infections among young people is around 35%.
For Ke Xi, a 20-year-old student at Hebei University in Hebei Province, central China, the lack of sex education made it more difficult to understand herself and how to carry herself. She described feeling anxious about mainstream societal norms around women and sex and whether she should have to confirm to them.
"Chinese men view ignorance as cuteness when it comes to being a woman," she said. "Some girls around me don't even know the process of intercourse, and they listen to their boyfriends. But their boyfriends learn from Japanese porn."
Other women want to ensure that their daughters don't lack the sexual education they themselves missed out on and know how to protect themselves.
Last year, a kindergarten scandal in Beijing saw parents alleging that teachers had molested
Wang Bing, a 36-year-old employee in a Chinese state-owned enterprise, said that when she was young, she was taught nothing by the older generation, who preferred to ignore the topic.
"Just like the saying, women begin to know their biological structure through her husband, after getting married," she said.
With two daughters at home, Bing passes on her limited sexual knowledge and buys books with cartoon pictures for her oldest, now 10.
"It's necessary to know something. At least you know how to protect yourself when danger comes to you," Wang said.
'The course changed me'
Frustrated at the insufficient education offered by the government, nongovernmental organizations, therapists and other advocates have begun to seek a way out.
Fang's courses aren't the only new option being sought by enterprising Chinese educators. In 2017, Beijing Normal University published a sex education book that provoked both praise and controversy
But unlike the textbook distributed in public schools, the courses haven't been controversial, as they are spreading through people who accept them and choose the best ways to pass on their newfound knowledge.
More than 70 potential sex educators finished their first comprehensive training in mid-June and will go back to their hometowns to spread what they have learned.
Wang Yi, a lecturer teaching environmental protection and engineering at Dongbei Normal University in Jilin Province, Northeast China, said she began to take the courses in sex education after she had a child.
She didn't want her child to have to "repeatedly walk on the old road as I did," she said.
Wang had to spend a night on the train to reach Beijing to take part in the course, but she said it was worth it. "You can learn a lot here."
She has already started to teach preschoolers in hometown, with support from parents who consider humanity the topic important.
Starting with the lesson of "Who am I?" she puts gender cognition together with gender equality. Children also learn about sexual harassment and circle which part of their bodies they don't want to be touched on a drawing.
"The course changed me," she said. "The concept here is very open, and it has become part of me."