M.A.
Hi Suzi,
My 3 years old does that when she is very tired or when she was playing with other kids for too long (what makes her tired), she seems to dream about things that happened during the day (me first, it's mine,he took it, I want it, etc) , I think that she should try letting him rest and may be taking a nap or quiet time during the day and make sure he goes to sleep before he gets too tired.
Hope it helps,
Mariana Abadie
www.MykidsFirst.com