I was terribly worried when Alfred wouldn't drink water during the day, and was drinking hardly any milk at the morning and night feeds. Then, he just went back to it and guzzles both. I came to the conclusion that they know if they're hungry or thirsty, and there's no point in worrying.
So long as the food you're giving your child has enough of the nutrients needed (and I guess it does if she's not taking milk), then.... I say relax.