I am researching a paper which I am writing on our culture's sexualisation of pre-pubescent girls (I have two children), and came across your website. I found all the comments on this issue interesting and illuminating. One or two Urban Myths are floating around:
How do we know the age of puberty is dropping? = we don't - no-one is collecting any statistics on it now, and no-one was before.
Cultures have been depilating for millenia = yes, SOME cultures; others don't care or like their hair - and South American Amerindians (very smooth) are fanatical depilators. Remember that if your pubic hair fell out because of disease in the C18, you got a pubic wig, a "merkin". It'd ALL a matter of temporary cultural preference.
The debate is (naturally) very much about contemporary English (and American) culture. I don't under-rate for a second the merciless pressure daughters are under from their peers, carefully tribalised to provide the easiest pickings for our consumer economy. But I am coming to the conclusion that the sexualisation of the immature is mirrored by the infantilisation of adults - and the increasingly pathological loathing of body-hair, especially the shaved pubis, seems to me to be a very sinister sign: one of its (not directly intended) messages is "have sex with children" - and lo and behold we have sexualised them all ready for it. Of course, we can't admit that our culture is doing this all for cash, so we invent armies of predatory paedophiles - whom we actually encourage by the pressure we put on little girls to become sex objects.
It's not a nice culture we live in.
However, after that digression: it's a pity that young daughters should have to consider such things, but contemporary culture is very much less tolerant and very much less individualistic than it used to be. You do as your peers tell you, or woe betide you... As long as the girl in question is given the perspective, is allowed to realise that this is an illogical external pressure, which she is at liberty to resist, now or later, as long as she does not become fetishistic about depilation, it seeems to me that the issue comes down to what is most physically pleasant and least physically damaging.
(Let's not get into the psychological damage...)