Thanks! I ended up calling the parent to clear the air, and while I think we both ended the conversation feeling better, nothing was actually resolved. She thinks 2 hours is too long for her son, and I expect 2 hours because anything less would be disruptive to the other kids.

For those who have early wakers, how did you initially train them to be content in their space?

The mom also either lies with her son, or he falls asleep with his older brother, and on the days when I don't have him (he is part time), the dad doesn't follow a schedule at all. I know this is part, if not all of the problem, but I can't exactly tell her what to do with her own kid when they are at home.