A woman is facing charges after overdosing while caring for a four-year-old in Ambridge.  The child called 911 earlier this month to say she needed help.  When responders got to the 18th Street home, they found Allison Welling unresponsive.  She was revived with Narcan and charged after officers found heroin and a hypodermic needle within reach of the little girl.  Police say there have been previous overdose incidents in the residence.