The fire broke out just after 2:00 p.m. in the 1200 block of Carolyn Drive.
A neighbor called 911 after seeing fire coming from the house.
Fire crews had to pull the three victims out of the house, and all were taken to Saint Mary's Hospital in critical condition. Firefighters say they found all three of the victims in a smoke-filled bedroom in the upstairs of the house.
The mother was transferred to Temple University Hospital. The infant has been sent to Children's Hospital of Philadelphia and is in a medically induced coma.
The fire was brought under control within an hour.
There is no word yet on how this fire started.
The children's father and another, older daughter were not home at the time of the fire.
