It happened 11:30 Saturday night on the 1000 block of Princess Avenue.
The fire started in the kitchen and fire crews quickly arrived to bring the flames under control.
Officials say the woman ran back inside the home to rescue her child and both were overcome with smoke.
The mother was taken to Cooper University Hospital in stable condition and her child is listed in critical condition at Crozier-Chester Burn Center.
Authorities are still unsure what sparked the blaze.
