So we use avent natural bottles. We currently use size 1 nipples which is 0-3 months I believe but she sucks way too fast and a lot of the milk falls out of her mouth. However, when I try the size 0 nipples, while it slows her down, she sucks so hard the nipple gets pulled back down into the bottle. Any suggestions on what nipple I should be using or suggestions for how to help her suck more effectively? I don't want her to get too much air as she is eating as she is already a really gassy baby.