16-24 oz per day of dairy is the general guideline. Tyler didn't drink milk consistently from a sippy until we ditched bottles completely. We dropped them gradually and gave him plenty of other dairy to make up for the lost ounces while he was still in between, and we'd have the sippy available throughout the day for him to, well, sip from. Once the last bottle was gone, his milk intake from the sippy went up big time, but he's never sat down to drink 8 oz at a time. Try not to think of the sippy as a bottle...babies gulp down 8 oz bottles because that's their meal, or at least a supplement to it. Adults drink when they're thirsty, which is usually a few ounces at a time. Part of transitioning to a sippy is to teach your toddler to drink when she's thirsty like we do, so what she's doing is normal!