Officers responded to the home on 1600 block of Harrison Street around 11:30 p.m. Wednesday.
The mother told police she left her two daughters, a 9-month-old and a 2-year-old, in the bathtub as she made a phone call.
The mother said when she returned a minute later, the 9-month-old was unresponsive.
Police said once the child was at the hospital, she had a pulse and was conscious.
The Special Victims Unit is investigating.