Houston, 43, was escorted to a benefit for juvenile diabetes research in Beverly Hills, Calif., by her longtime record producer, Clive Davis, People magazine reported Monday on its Web site.
"I feel great," Houston was quoted as saying, while Davis, one of Saturday evening's honorees, told People: "We're going to make a killer album."
A blond Houston, wearing a black gown and diamond earrings, sat at the main table for the 17th Carousel of Hope Ball with Halle Berry and Berry's boyfriend, model Gabriel Aubry, People said.
"American Idol" runner-up Katharine McPhee sang Houston's "I Have Nothing" at the event.
"It's her first big appearance since the breakup," McPhee, 22, was quoted as saying on the arrivals carpet. "I would love to sing with her, but unfortunately all eyes are on me."
Houston filed divorce papers in Orange County Superior Court two weeks ago, a month after filing for legal separation from Brown.
In the separation papers, the pop singer asked for custody of the couple's 13-year-old daughter, Bobbi Kristina, and that Brown, 37, be allowed visitation rights.
The couple wed in 1992, with Houston at the height of her fame as a Grammy-winning superstar known for hits such as "I Will Always Love You."
During their marriage, Brown was arrested for drugs and alcohol, and Houston entered drug rehabilitation programs twice.
Brown won acclaim for his gritty R&B songs as a one-time member of the boy band New Edition.