Glad your daughter was finally able to "go". Milk can definitely cause consitpation- and if she has a milk sensativity- it can also cause cramping, bloating, and a plethera of other issues. I'd suggest getting her some Lactaid Milk. That's what i drink- i'm lactose intolerant and have a ton of issues if i try to drink normal milk. It tastes just like regular milk (i promise- i've tried everything...and trust me- there's no comparision between lactaid milk vs. soy or rice- it's sooooooo much better.
) They make it in different kinds like fat free (what i drink), vitamin d, 2% and everything- it's just easier to digest.
Try her on some of that. She won't be able to taste a difference- but ya'll will see a difference when her tummy doesn't get upset