Brown, 21, was found unresponsive in a bathtub in her Georgia home on Saturday morning. Her husband, Nick Gordon, and a friend called 911 and she was taken to North Fulton Hospital in Roswell, where she was put on a ventilator.
Brown was placed in a medically induced coma on Sunday and has had "significantly diminished" brain function, TMZ reported, citing unnamed sources.
Brown's father, singer Bobby Brown, and actor Tyler Perry were at the hospital with Brown. Sources told People magazine that Bobby Brown was "inconsolable." The magazine is also reporting that while recovery is "technically possible" it would be "a miracle."
Bobby Brown issued a statement to E! News asking for privacy.
"Please allow for my family to deal with this matter and give my daughter the love and support she needs at this time," he said.
"The report that Bobbi Kristina Brown has been taken to the hospital in Atlanta, Georgia is accurate," Bobby Brown's lawyer said. "No additional information will be forthcoming."
Brown's mother, Whitney Houston, was found dead in a bathtub at The Beverly Hilton on Feb. 11, 2012, after she accidentally drowned. The singer's heart disease and cocaine were cited as contributing factors to her death.