The 21-year-old Brown was hospitalized over the weekend after being found unresponsive in a bathtub.
“Bobbi Kristina is fighting for her life and is surrounded by immediate family," the Houston family said in a statement. "As her father already stated, we are asking you to honor our request for privacy during this difficult time. Thank you for your prayers, well wishes, and we greatly appreciate your continued support."
Brown, the daughter of Bobby Brown and the late Houston, was rushed to an Atlanta-area hospital after her husband, Nick Gordon, and a friend found her face down in a tub. Police arrived at the home at 10:25 a.m. and took over life-saving measures until rescue personnel arrived.
"Can't say how sad this is," Roswell Police Department spokeswoman Lisa Holland said. "It's a difficult situation for a police officer to perform CPR on any person."
Brown lost her mother almost exactly three years ago in a similar fashion. Houston was found unresponsive in a tub in Beverly Hills and died shortly thereafter.