Friend finding tit, bondage pics on step sons phone of his bio mom?

I need some advice. My friend just sent me a text freaking out saying that her Step Son (who just turned 9) came over for the weekend (they have him every other weekend per custody agreement) and he got a new phone. She said it must be his moms old phone because she was going through it because she used it to take pictures of her son and step son together, she was going to send them to her phone and went through the photos and found old pictures of his moms boobs, bondage photos, her new boyfriends d*** pics and everything.. They’ve been trying to fight for full custody but just settled out of court because as a lot of cases do, the full time parent who’s a mom usually gets more say in the matter.. (I’m not saying this is always the case, it’s just unfortunately what happens and happened to them). Anyways, what should she do? I’m jaw dropped for her. I don’t know what to tell her and she doesn’t know what to do! What if the poor boy sees these photos or already has?! It’s sooooo messed up and sickening if you ask me.