The shooting occurred around 3 a.m., and an investigation is ongoing, police said.
Hanover Township police, working with the District Attorney's Office and the Pennsylvania State Police, described the incident as an isolated case with no threat to the public.
Details surrounding the circumstances of the shooting remain unclear.
The girl's identity has not been released, and no further updates were immediately available as of 5:58 p.m. Monday.
This is a developing story.
Click here to follow Daily Voice Boiling Springs-Mount Holly Springs and receive free news updates.