"She did what she had to do," Marx said. "She saw no other way out. She was happy to be able to provide. She'd say, 'I'm selling myself for you.'
When Marx stumbled in the playground and her skinned knee bled, children fled, screaming, "Don't go near her, she has AIDS!" (She didn't.)
She was an outsider, not just because she was a prostitute's child, but also because she never quite belonged racially.
"I didn't look like them. So you don't fit in. Trying to fit in to the society is very difficult," she said. "People say, 'You're not African, you're Indian.' … I just write it off. I don't consider myself Indian or colored or anything. At heart I'm pure African."
Marx was 10 when her mother was killed. Her grandmother, who died two years later of AIDS complications, offered little supervision.
"They were never there, or if they were there, I was neglected. It was a dysfunctional family at the time, because everybody wanted to live their life without having any responsibility."
After her grandmother's death, a great-aunt, whom she calls Mom, raised her more strictly. But she still skipped school, stole cigarettes and beer, and gained acceptance by hanging around with the tough, popular crowd at school, bullying other students and harassing teachers.
"When you had a boyfriend, you were cool. People would get a boyfriend, lose their virginity and come to us, 'Look, I'm cool now.' And I'd say, 'Yes you are, you're one of us now.'
"It really boils down to how a person grows up and where a person grows up. If you look around this community, there are many children who have children. There are many teenage moms. We all go around the same circles. Just a few get the opportunity to go to university and say, 'Let me go get a career and that job I have dreamed of.'"
When Marx arrives home after a deadening day at the factory, she tries to be cheerful, for her daughter's sake.
"It's very belittling," she said, comparing her job with the university life. "I do feel that I don't belong there, but maybe I am there for a reason, because I am learning to be disciplined."
The child's father, a fellow student who dropped out to join his father's commuter transport business, advised her to have an abortion. He provides little support.
"I go to work and I have my frustrations. When I come home, I have to put on a smile. You can't go to a baby with a sore heart. I love her to bits. I cherish her. She's the only close relative I have."
The day she gave birth, Marx was supposed to be taking an exam.
"It was like balancing it up: What's worth more? Your exam? Or your daughter's life?"
Marx would have to repay about $1,500 in fees for the year she failed in order to gain readmission to university. She is determined to save up and return to get her law degree, once Thembeka is old enough.
"It's like she's doing me a favor.... It's like she's saying, 'Don't worry, Mommy, I'm growing fast. Soon you can leave me in a creche. By the time she's 5 or 6, maybe I'll have a degree."
She thinks of her daughter's name.
"With her came hope, and with her came faith, even though there was disappointment. But I accepted her.
"I was like, 'Have faith, Nicolene. Have faith, for your little girl.'"