The children were trapped on the second floor of the West Washington Street blaze in Paulsboro, which broke out around 4:30 a.m., officials said.
They were rushed to Kroger Hospital, where they were in critical condition as of Saturday morning.
Four adults, meanwhile, were able to escape without injury -- including one who carried an infant out of the home, fire officials said.
The fire is believed to have started in a common area on the first floor of the house, Mayor Gary Stevenson told CBS news.
A GoFundMe for one of the residents -- described as a woman with a "heart of gold" -- had raised. more than $6,400 as of Sunday morning.
Click here to follow Daily Voice Bergenfield and receive free news updates.