She was born with cerebral palsy and wasn't expected to live long after birth. She also required daily physical exercise from her mother 3 times a day. When Jo visited the Bruno family, Mariah revealed that she wanted to spend more time with her dad.
She was one of the most well behaved kids on the show.
She was 15 years old when she appeared on Supernanny and she is now 26 in 2017.