So I informed you people of my recent conundrum. My solution ended up being that I had a discussion with the child about the fact that there are adults who want to hurt children who lurk the internet, and what kind of information she should be wary of handing out on the internet (Incidentally the person the child handed out their number to was another child, the kid had vetted this on their own before handing out their actual phone number, which is pretty cool. Also both kid's moms have now spoken so that's double cool). I then promised the child that I would never tell anyone anything that they tell me in confidence. Which I mean I guess I already did kinda, but it feels different because I am sharing it anonymously. I then said I would tell their mom that it was time to talk to them about what they were allowed to do on the internet so nobody would get in trouble in the future.
Well someone got in trouble, and that someone is me. Because the girl told her parents what she did during that conversation, and they panicked and told the institution, and everyone agreed that I had been negligent because I had only told them to have a conversation about internet safety and not told them specifically what happened. Even though they found out literally two days after I did.

Now the worst didn't happen. The kid still has her phone. But it's now basically 90% spyware and parental control which is gonna do a fat load of good since nobody bothers to check it and the parents immediately wanted my help in getting around parental controls to use a third party chat feature anyway. While still being mad at me for not telling them. But also she's not allowed to install google messages because they don't know if they can monitor that?!? The whole thing is a mess, but at least no one got hurt.