A Montgomery County woman has admitted dragging her two-year-old son halfway across a busy road and then leaving him there. 32-year-old Nicole Weir of Tyson Road in Abington pleaded guilty to endangering the welfare of a child.  The judge gave her nine to 23 months in county prison, followed by two years on probation.  The incident happened in early April, shortly before 9:00am, when several motorists called police to report a child standing in the intersection at Easton and Susquehanna Roads, about 20 feet from a SEPTA railroad crossing and not far from her home.  One motorist stopped and picked up the toddler.  Court documents say Weir had a quarrel with her boyfriend shortly before the incident.