Yeah, I didn't answer originally because I didn't understand your question but figured someone else would.
Honestly, I don't have any recollection of any studies on this, so this is conjecture and nothing else.
I don't think your kids are going to be any shorter because of their diet (who knows, they might end up short anyway for genetics).
Cow's milk is indeed geared toward large-massed creatures. However, I don't think the mass=height in humans (maybe more flesh on our bones, though). Also, and this is highly debatable, I think at this point those of European descent and certain African descents have adapted to drinking cow milk, and can do so without odd results.
Next, most Americans drink pasteurized milk, which means they are not enjoying the true nutritional benefits. And thus I doubt they will see extra height or health from it. Yes, I know the hype about how much calcium is in cow's milk, but unless you drink it raw, you're not getting it in a form that's very bioavailable. So, no, I don't think calcium or anything else in conventional milk is making your average American any taller.
Next, the growth hormones I believe will enhance puberty but not height. The point of the hormones is to increase milk, not overall size, in the cow.
So that's my musings on the milk part. Dunno about the organic food part; I can't imagine why organic food would stunt anyone's growth or conventional food would enhance it. I'm stumped here.
If you are worried and would like to give your children milk but are reluctant to expose them to the hormones and chemicals and so on, look into raw milk. There are many differences, not just lack of hormones. I mean, I don't think you have to give milk at all, but I do think there's a world of difference between conventional and raw.
