It really is just wind down. Both of my children have done it. My 6 year old doesn't do it anymore - I can't remember when he stopped. But my 4 year old daughter does it from time to time now. She sings and chats to her rabbit
, and it can sometimes be up to an hour before she falls asleep!! Not normally, but sometimes. And it really does have nothing to do with UT/OT, she is just relaxing and unwinding, it's probably got more to do with how much stimulation she has had during the day (she's at school now and has plenty to think about at bedtime
).