6-700 mLs is roughly 20 - 23 ounces, which is exactly what she needs in a day, so that part is fine I would say! From 6 months to a year the guideline they use here in the UK is 20 - 24 ounces in one day. But, you're right that taking it in 50ml feeds at a time is not ideal for either of you!
My DS does VERY much off of food when he is teething, and with his last ones, it took a while of him getting used to the idea of these teeth in his mouth to get back onto food. Like it was a weird sensation in his mouth and a bit strange for him.
Do you have a routine each day for feeds? One thing that I would try to do if I was facing this is to cut one of the feeds out (as in, one instance of 50mL of milk) every two days. Slowly get her used to the fact that she has to take more or will be hungry. Follow her morning, lunch and dinner milk feed with a solid meal an hour later.
I would expect that the first few days she won't take much more, but she also won't starve herself. Then try to amalgamate her feeds together. Often I think that when babies know they have another feed coming soon they just don't bother drinking much because they know it only needs to last them a short while before they get more, which could explain why she only takes 50 mLs -- she knows that in an hour or so she can have another 50. If you start making her wait a bit longer, she will start taking more.
It's sort of the principle with dropping a bottle - when on 4 bottles a day (example) and LO starts taking less and less at each feed, by cutting one bottle out and only offering 3, they take more at each feed and thus increase their total overall milk. So, you could use this same principle but a bit more gradual if she is used to the more feeds, iykwim?
