Someone was bullying my little brother when I was about 13. Big boys too... They went to take off on their bikes as I approached and I remember (vaguely) picking up a stick and jamming it in the front wheel of his bike as he took off... he went a*se over t*t off his bike and landed on his face. Went home crying to his mum who turned up at our house to talk to mum and dad.
I was packing bricks becasue I had VERY strict parents who would gladly give ME a right whack to show me violencse was NOT to be resorted to.....though I give them credit... they stood there and said that everyone KNEW what a quiet child I was and it was inconceivable that I would do something like that... and besides could they explain my little brothers bloody nose????
They gave me two lines about how I shouldnt EVER hit another child and it was never spoken of again.
No M cant raise a finger.. its assault and she is technically an adult and would be charged as such. And the ex would have a field day with my parenting skills.

for your daughter. Sorry this has happened to her.