There actually isn't any dairy requirement afaik. There is a calcium need, and it is most easily obtained from dairy. For children aged 1-3 the need is about 500mg of calcium per day. One cup of milk (250mls) has appx 300 mg of calcium. So two cups is enough in a day (500mls, or about 16 ounces). However, there are other sources of calcium as well (aside from obvious cheese and yogurt), sardines and homemade chicken stock are also very high in calcium and oatmeal, beans, some fruits and veggies, etc that really help to top-up if she is not taking in enough from dairy.
HTH.