DD1 (4 months, 12 lbs) has been just fine using Pampers until now, but now it seems that size 2's are getting small and size 3's don't fit at all. She's a bit on the lean side (but not too much) - any suggestions on what brands to try for her size and shape? I'd really like something that'll keep the night time poo in so we're not doing full clothing and linen changes in the middle of the night as they wake her up so much she doesn't go back to sleep for 90 mins!