Her parents told her "there were no limits," she said, and proved hard work could pay off. Her mother started in an insurance firm's mail room and became a manager. Her father began as a New York Transit toll collector and retired as a supervisor.
Still, "with all the supports I had, it would have been very easy to fall into the wrong crowd, whether for survival reasons or as a defense mechanism," she said. "Statistics say where I should have ended up, and it's not here."
Today, Brawner's focus is stopping the spread of HIV, the AIDS-causing virus. With a $1 million grant from the Centers for Disease Control, she created Project Gold, a program to teach teenagers with mental illnesses how to avoid HIV and other sexually transmitted infections. In a city where the HIV infection rate is five times the national average, hers is crucial work.
Brawner's team is recruiting participants, a challenging, sometimes tedious task. But if frustrated, she need only think of the 14-year-old who wondered to Brawner if her destiny was already set.
"She was like, 'What's the point? Everywhere I look, people tell me I'm at risk . . . I feel like it would be so much easier to just get it and then I don't have to worry about it anymore,' " Brawner recalled.
"For someone to look at HIV that way, it just tore my heart out. It tells me we need to work harder."
Her parents separated when she was a toddler. Though her father stayed involved in her life, Brawner said she felt abandoned and, as children do, wondered what she had done to drive him away.
A few years later, a family friend molested her multiple times - a secret she kept until recently.
"The first time I said it out loud - 'I was molested' - was at a program at church. I cried," she said. "When you name something, you make it real."
Brawner was about 10 when her mother took a job transfer to central New Jersey. The transition from Flatbush was rough, she said, but she found her place, completed high school, and earned a bachelor's degree in nursing from Villanova University. She was the first in her family to finish college.
"If we hadn't moved to New Jersey, I wouldn't be in the same place," Brawner said. "Yes, I have friends from elementary school who are doctors and lawyers and CEOs. It's not like anyone who comes out of the inner city will have a horrible way to go, but there are more temptations to take a different route."
A short time working in a hospital setting, seeing the challenges teenagers faced, inspired Brawner to return to school. She got her master's and doctoral degrees from Penn, then was asked to join the teaching staff. She decided to use research as an advocacy tool.
Loretta Sweet Jemmott, director of Penn's Center for Health Disparities Research, saw herself in Brawner. Jemmott, too, had overcome great odds after growing up in West Philadelphia public housing. Brawner, she said, had an air of "I'm going to be successful in spite of."
Now, Jemmott said, "She's looking to shape science and change things."
In the early '90s, when Brawner was a preteen, a cousin died of AIDS-related illness. The man was barely 30.
"It was very hush-hush, even in the family," she remembered. "You don't name it. You don't talk about it. You don't say what actually happened. But you know."
When HIV first appeared in the U.S., many dismissed it as an exotic virus only homosexuals could catch. Later, as the disease's African origins came to light, some thought it mainly an immigrant problem. Brawner and others in her field say the virus now is spreading most rapidly in lower socioeconomic ranks, here and around the world.
"HIV trends with social injustice," she said.
The name Project Gold is meant to invoke images of royalty. "We are kings and queens," proclaim the handouts and T-shirts.
The message to teens, Brawner said, is that "we want them to aspire to things greater than themselves. They get beat down so much in our society, told they're bad or doing things wrong. We want them to be able to say, 'I'm not going to be in a relationship with a boy who is seeing three other girls.' 'I'm not going to be in a relationship with a girl who thinks it's OK to slap me in the face.' "
Project Gold participants are to be paid up to $200 based on how many steps they complete, including two three-hour-long sessions in one month, followed by interviews every three months for a year.
HIV, she said, is "100 percent preventable." She hopes her research leads toward that goal.
"One of the things that helps me sleep at night is I'm not just doing this work to put it in a journal or go to conferences," Brawner said. "I'm doing it to make a difference on the ground."