7yo DD really bad behaviour at school

[BerthaMason]

DD was banned from a school trip for various bad behaviours the worst of which was throwing stones at cars that were driving past the school.
DD goes to an inner city school in a poor area.
She says another girl made her do those things.
She is normally well behaved, her school report is really good, I at a loss as to what to do as she doesnt seem to be taking this seriously despite my efforts.

how did the school sanction her apart from the trip ? You need to agree a method of discipline with them if this is persistent. At 7 she is well old enough to know actions have consequences and control impulses to such unacceptable behaviour.

If her report is good, then this is a recent change in behaviour at school?

Seems a little odd if her report is good, yet she behaved badly enough for the school to ban her from the trip. Has there been any changes recently at home or at school to prompt this behaviour?

How does she behave at home?