Bobbi Kristina Brown is 'still fighting the battle of her life,' says Patricia Houston

ATLANTA, March 5 (UPI) -- Patricia Houston says her hospitalized niece Bobbi Kristina Brown spent her 22nd birthday "fighting the battle of her life."

"Today is Bobbi Kristina's 22nd birthday and we ask you to continue to keep her in your prayers as she is still fighting the battle of her life," Houston wrote in a message posted on the website of The Whitney Houston Estate, alongside a beautiful photo of Brown and her mother in happier times.

Brown has been hospitalized on life support since Jan. 31. She was discovered face down and unresponsive in a bathtub at the Georgia home she shared with her boyfriend Nick Gordon.

Brown's father, singer Bobby Brown, has insisted their family is continuing to pray for the young woman and has no plans to remove her from life support.

The circumstances surrounding the medical emergency remain under investigation. Some media reports have alleged Gordon and Bobbi Kristina Brown were engaged in a physical altercation before the incident, while others claim she was using drugs and intoxicated the morning she was found in distress.

Gordon was the unofficially adopted son of the late Whitney Houston, Bobby Brown's ex-wife and Bobbi Kristina Brown's mother. Houston accidentally drowned while intoxicated in a Los Angeles hotel bathtub Feb. 11, 2012. Patricia Houston is Bobbi Kristina's aunt and was Whitney's sister-in-law.