Little Child

What milk he/she doesnt drinks?Do you mean human milk?
What the doc says?

If he doesn't like milk, give him other dairy products like cheese, ice cream, and yogurt. There are also some other calcium rich foods such as salmon, tofu, rhubarb, Spinach, broccoli, peas, turnip greens, collard greens, and almonds that he might eat.

It's very important that children drink milk. If they are refusing to drink it maybe you are giving them other things and shouldn't do that. Otherwise you might check with the doctor, maybe the milk upsets their stomach and that is why they are refusing it - you may need to change to a different milk.