I have an almost 19month old son and from 12 month onwards we dropped his milk right down. Nowadays he rarely drinks milk. Maybe a couple of times a week and only about 150mL at a time. He gets his dairy/calcium in other forms.

Too much dairy can cause constipation and it does seem like quite a bit of milk. Does she drink water. By now she should be drinking a fair bit of water each day and that will definately help with the constipation.