05/08/2000 at 01:00 AM EDT
NO ONE KNOWS BETTER THAN TIONNE "T-BOZ" WATKINS THAT LOOKS can be deceiving. The "T" in the R&B group TLC found inspiration for the lyrics to their No. 1 single "Unpretty" in her blood—literally. She was diagnosed at age 7 with sickle-cell disease. Two decades later, while watching a Ricki Lake show featuring women being berated by their spouses for being overweight, Watkins, 30, was inspired to write "Unpretty" as an empathetic poem based on her own insecurities. During her teen years in Atlanta, says Watkins, "I was known as a sicko who couldn't do what normal kids were doing. I couldn't go swimming because the water was too cold, I had to drink special baby milk for my bones. I felt ugly." Her "Unpretty" words ("You can buy your hair if it won't grow/ You can fix your nose if he says so"), which were put to music by producer Dallas Austin, resonate with fans. "I get a lot of tears, a lot of hugs," says the 5'2" Watkins, who went public with her illness in 1996 to refute rumors that she had AIDS. Now working closely with the Sickle Cell Disease Association of America, Watkins "helps get the word out," says the group's president, Lynda K. Anderson. "The motivation she provides kids is outstanding." But motivation is something Watkins must often summon up herself. In November she went straight from the Atlanta hospital where she was being treated for a sickle-cell-related spleen disorder to the nearby stage where TLC was taping a concert for HBO. "Somehow, when it was time for me to do my solo, I got it together," she says. "My mental state is strong. I stay very positive." Not to mention pretty—and pretty experimental. Now blonde, she has tried a spectrum of hair colors, including red and purple, She also concocts different mixtures of perfumes daily "so no one will smell like me," she says. Her fiancé, rapper Mack 10, age 28, approves. "I'm still looking for a flaw," Mack says jokingly, "and I can't find one," Watkins, who is pregnant and planning a summer wedding, doesn't care if he does. "One thing I'm trying to teach kids that nobody ever taught me is that nobody's flawless," she says. "If somebody says to me that I have bags under my eyes, that I look tired, well, honey, I am tired."