J.M.
I started using a pillow at 2 yrs old, and she is almost 2 and a half now, in a toddler bed, but didnt move her into that until she fell out of her crib one time and that was enough for me. I just use the fitted sheet on her mattress, but she does have a blanket. I dont bother with the extra sheet, one its FL in the summer right now, and two, I am sort of cautious because I think crazy stuff like she can get caught in it and stuff, so I dont bother with it.