Kester Kovers are lovely and trim and great for night; I find the BBBs good for night. so if she likes them that would be a great option as I think they're one of the trimmest night nappy options around.
Loveybums wool covers are superbly trim and so soft; we often use one overnight under PJ pants instead of a soaker. I got mine from Vanessa at Cute Tooshies and love it to bits
