I've heard of people putting the sleep wedge underneath a mattress for their baby.. I'm not sure if it's only a certain kind of wedge or anything. But I just wanted to suggest it in case you wanted to give it a try rather than having Haylea sleep right on top of it.
However - if I were you, I'd probably be too nervous of changing it up incase she went back to sleeping poorly. We were always too nervous to mess around with something that worked!