firefighters rescued the woman 's three daughters and a son , ages 9 to 13 , at around 1.30 pm sunday .
the woman , a single mother who reportedly works at the philadelphia international airport , is now facing four counts of endangering the welfare of a child .
firefighters broke through this second-floor window to enter the locked home and extract the hungry kids .
all four children were taken to st christopher 's hospital for children for evaluation and were found to be in good condition .