I have an older casual girl that brings toys every time she comes here. I tell her the moment she walks in that if toys go down to the playroom, she needs to share and let everyone have a turn. If she'd rather not share, then that's fine, but I will put them away until she leaves. Most of the time it works, but they all know there's a no-strike rule. If they fight over them, they get taken away.

Frankly, I wish she didn't bring them, as none of the other kids do, but I'm in the same boat as you - she's so infrequent that it's usually a non-issue, so I don't really want to get into it. Honestly, I have bigger issues to fry with this family, such as paying on time, so the toys are pretty minor at the moment!