In all honesty, if you can, I'd get someone in from the police cybercrime people to have a word with her.
I don't know what it is about girls this age - they don't seem to understand exactly how much trouble they could create for themselves.
Situation local to me - one 12/13yo girl must have a fake age on her tiktok account as she is quite frequently seen gyrating in just a bra and micro shorts on there, and tiktok are supposed to police how much flesh is on show.
Ex-friends of hers (also 12/13) decided to "teach her a lesson" so set up a fake account pretending to be a 17yo boy and asking for nude photos, which the first girl then sent. (FFS!! Do they NEVER fecking learn?!)
These nudes then went around several other students at three schools, one of whom reported it to the police. Police came and had a stern word with the girls who did this - and hopefully the girl who sent the nude photos! - but nothing further was done because of their age, and, I believe, because they were girls and not boys.
One of them is my friend's daughter. She is autistic and because there have been no consequences, she can't really see what she did wrong. It hasn't negatively affected her (apart from the humiliation of the police interviewing her) and so there is no telling whether or not she learnt anything.
The girl who sent the nudes of herself - I hope the police have had a stern word with her too, and explained just what sort of trouble she could have got herself into, if that was a grown man obtaining photos of her, rather than 2 pissed-off ex friends. And, as the photos are now "out there", grown men could quite easily get hold of them :(
So police, if they have a community officer who would be willing to talk to her.