HI Maddymummy,
I had this problem with my DS when he was about the same age. I bought a GroBag sleeping bag and haven't had a problem since. He just didn't stay in the one spot in the cot so blankets were useless - not to mention potentially dangerous!
There is nothing you can do re the rolling over. She is probably waking because she is cold rather than the wrapping thing. I'd try a sleeping bag!!!
TICKLISH