My daughter has never been able to tolerate cow's milk--dairy constipates her sooo bad. She can have the occasional cheese slice, but thats it. We give her a daily probiotic and she only drinks soy, almond, or coconut milk. She gets her nutrients from food and she also takes a daily multivitamin and vitamin D. She is very healthy =) Trust me you don't want constipation issues, omit the cow's milk now! I don't want to scare you, but we have been to gastro ped's, did miralax for over a year, been to the ER many times when she hadn't gone for a week and was running a 105 fever. You said it yourself, she doesn't need the cow's milk. She needs a balanced diet with plenty of fiber and veggies, maybe a multivitamin with calcium and a vitamin D supplement and probiotic. Every morning my daughter takes the gummy vitamin, orange flavored chewable probiotic, and a liquid vitamin D supplement. Never given us any problems with it--they all taste good. She gets the almond milk, mostly because she loves it, one glass a day. (it is more expensive) Lots of people are lactose intolerant and they do just fine, so will your daughter. She will stay hydrated with water or watered-down juice. Best!