A hospital spokeswoman says the children's 34-year-old mother remains in critical condition Saturday at Temple University Hospital. The slain children were 7, 10 and 15.
Police say the two suspects fled on foot after crashing the stolen car Friday morning at a North Philadelphia intersection.
Authorities say they first carjacked a real estate agent at gunpoint and forced her into the back seat.
They say the men were speeding when they crashed a mile away.
The 45-year-old agent and a 65-year-old friend of the family were also hospitalized. Their conditions weren't immediately available Saturday.
Officials have not yet released the victims' names.