D.T.
You can also put layers on her mattress. I have twin boys, and the best advice I got was from my best friend (who has triplets). She told me to put as many layers (of sheets/sheet saver...or cotton/rubber mattress cover) as I can as it would help me when middle of the night problems come up. Now, if there is an issue (and my boys share a room so I try not to wake the other one up with to much noise) all I have to do is strip the top sheet and mattress cover off, put the stuffed animals, pillow and blanket back in and I am done is 2 minutes. Hope this helps :) Good luck!