Re: Breast to bottle
Totally normal, for any number of reasons. Part of it is that nursing is comforting, it's not just about eating and babies, especially very young ones, have an instinctive need to suck. A more functional reason for it, though, is that babies will drink more from a bottle than from the breast. Most babies will take around 2 ounces per nursing session. But they can't control the flow from a bottle the way they can from a breast. They tend to just continue to drink until it is all gone.
It sounds like your baby is taking a good amount of breastmilk during the day (you are supposed to shoot for 1-1.5 ounces per hour you are away), but this is a good link to share with your mom and husband about how to bottle feed a breastfed baby. It's just some helpful tips about how to mimic nursing with a bottle and prevent over-feeding.
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