I've know you for ages, but never asked where you come from? Are you UK?
If so then could it be that she is too hot and chuck the blankets and then gets too cold? I have this problem, I don't know what to do in the nights with this unusual close weather that we are having.
I know that she is capable of pulling the blankets back but in her sleepy stupour things are different!! Do you go and tuck her in when you go to bed? Try it, really tuck her blankets under.
also, do you think that, at her age, her nap could be a little shorter. Perhaps it might be robbing her nighttime sleep.
Alex wakes sometimes during the night, either for her blankets or if she hasn't had a nap, she will wake briefly. I also have a problem of getting myself back to sleep, perhaps we should start a thread on tips for getting back to sleep after being woken at 4am by pesky toddlers!!!
Mari