Err on the side of a lighter bat. You want to develop muscle memory swinging a quick bat ... not laboring with a slower swing. Especially at the 10U and 12U level. You want to develop the good habits of a quick swing at the younger ages. Hard to get that back once your body is used to the slower swing with heavier bats when you're young. I really don't think you're doing your daughter any favors by having her use a 22oz bat at 10U ... doesn't matter how big she is. As others have said, her muscles aren't developed.
Consider this: College kids in weight-training regimens are only using 24-25oz bats. A 10U kid shouldn't be near that, and in my opinion neither should 12U kids. Yes, the slower heavier bats might be working against the pitching you're seeing now. But those slower swings, and that muscle-memory of learning how to swing a heavy bat, may keep you from succeeding later against better, faster pitching. JMHO.