Police initially reported she was shot, but investigators now say her face was slashed.
The attack happened in the Fresno County town of San Joaquin early Thursday morning.
Deputies say an intruder woke up Marcella Miller and her daughter.
They say Marcella was attacked when they got up to investigate.
Investigators believe the person climbed into the victims' home through a window.
Miller is listed in stable condition at Community Regional Medical Center in Fresno.