The accident happened just after 6:30 p.m. as they were walking across the street at Valley Road and Birchwood Terrace in Wayne.
Both victims, who live in the neighborhood, were taken to St Joseph's Hospital where the mother was pronounced dead. The child is now listed in serious condition.
The driver and his passenger remained at the scene. Neither were injured.
No charges have been filed, but police and prosecutors are still investigating.
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