This is what you call crowdsource parenting.
My teenage daughter has been friends with this other girl since she can remember. I think they met in Kindergarten. Nice kid. And by “nice kid” I mean that I’ve never seen her be mean to anyone on purpose. And being a parent of four girls, I’ve met many girls whom I couldn’t say the same thing about.
However… (you knew it was coming, right?) the last three years or so her language has become coarser. My daughter or I will typically point it out politely and she always apologizes. And I can tell she means it. Also her manner of dress has become a bit more… revealing. She talks a lot about getting tattoos and multiple piercings.