Yes, but

It sounds like they're mostly brainwashed by whatever anti-sex Christian sect they follow.

Yes, they are conservative, but child marriage to little girls has occurred even in the most conservative Christian communities (historically). As far as I can tell, this was especially true in the American South. Things have just changed in recent years, but that's not how it's been historically. The most conservative of families used to marry off their daughters very young. So obviously, the conservativeness of the Amish cannot be the reason for not practicing child marriage.

And I don't mean to say I support all the known forms of child marriage (force, rape, etc), but such practices do expose the fact that sex with little girls has been allowed.

Either way, there has to be some pedophilia occurring within these communities, even just in secret, as in modern society today.

I get the feeling Amish-like communities are under a great deal of scrutiny... governments typically do keep an eye on them, and the modern cities find them "weird". Therefore the elders of the Amish communities feel a lot of pressure to "be good" and keep their activities away from prying eyes, or anyone who will give them "heat". Very similar psychology is at play today within Islamic communities, mosques, etc, in the West.

In short, I don't understand at all how conservativeness and being traditional automatically results in anti-pedophilia. Yes, there have been many examples in history of this being the result, but there have also been many examples of pedophilia being practiced within traditional societies. And by pedophilia, I mean child marriage (not fornication with children).

Actually, some Mormon communities can be compared to the Amish, and they do practice child marriage.