My 2 year old has just started sleeping with a 48x60 "fleece" blanket within the last couple of months. He always had a flannel recieving blanket (45x45) before that. However he sleeps ON it instead of under it.
I am a young mother and a quilter. My children did not sleep with quilts however I still made them for them. There are so many other ways to use a quilt rather than just covering them up in bed. I also made all their recieving blankets because you can't (hardly) buy them in the store big enough to swaddle!
If you are worried about risks of SIDS from things being in the crib pay attention to what your using to make the sleep sacks, OVERHEATING is also a "risk" for SIDS!
No one really knows what causes SIDS therefore eliminating everything that MIGHT be the cause is what is advised!