the minimum recommended is about 350mls (about 12ounces) from 1 year. This is inclusive of milk on cereal, in foods, etc amd also includes dairy products like yoghurt, cheese, etc. My dd has an open top beaker with a couple of ounces of milk along with her breakfast and a small avent magic cup of milk before bed and that is all the milk she drinks - the rest is made up of dairy, cereal, etc.
Your lo sounds as if she is getting plenty. You may find that as your lo gets used to taking milk from the cup, that her intake will pick up a bit as well.