Hi, peeps!
Throwing my two cents in...
There's a discussion thread somewhere here (sorry, I forgot where it is!

) but as I recall, it touched rather briefly on the matter of whether Harry and Ron "knew" that Hermione was a girl before the Yule Ball.
My opinion at the time (and it hasn't changed since

) was that Harry knew Hermione is a girl, and has
always treated her as a girl (deferential, polite, protective, etc.) while Ron's treatment of Hermione borders on the abusive and as 'one of the boys.'
The difference lies in their upbringing--and schooling.
We know that Harry went to school prior to Hogwarts and, while it may not have been said in canon, it is a safe assumption to say that it was a public, probably co-educational school... and, while Harry may have been an isolated, 'put-upon' kid because of Dudley's bullying, we can make an assumption that he's had at least *some* interaction with girls.
Granted, he may not have thought of girls from the hormonal, shippy perspective but at least, he knows enough about them to know that they're 'different' from boys.
Recall how quickly he picked up on the possibility that Hermione may not have known about the troll in first year, after he and Ron had overheard Parvati and Lavender talking about Hermione crying in the girl's toilet after their Charms classes.
On the other hand, JKR has said that Ron and Ginny had been 'home schooled' by Molly until they went off to Hogwarts... and it doesn't take a major leap of imagination to think that all the Weasley children were home schooled before Hogwarts--a disproportionate six males to one girl, and the last being the youngest, at that.
And, while the Weasleys may not have been the only wizarding children in Ottery St. Catchpole, chances are high that they also did not have much interaction with other children... after all, Ron does not seem to remember Luna Lovegood, and Ginny knows her only because they are in the same year at Hogwarts.
In any case, in a household with a disproportionate number of boys, chances are that Ginny would have been treated as more 'boy' than girl. True, she does show signs of 'girly' behavior (especially with her crush on The-Boy-Who-Lived) but also consider her other, rather 'masculine' traits (practicing on the boys' broomsticks, showing more power and capability with her Bat-Boogey Hex, etc.)
Ron, therefore, would have had
no idea on how to handle a girl--or woman (except for Molly), something which (again) can be seen in the Ron and Hermione interactions during the early years--constantly bickering about almost everything until fourth year and Ron's 'epiphany.'
One thing to think about: there was
no R/Hr until fourth year and Ron's epiphany, followed soon after by the Yule Brawl and Ron's 'jealous' actuations (which have been dissected here and in the PA forums).
Another thing to think about... Ron's 'epiphany' in fourth year was that Hermione was a
girl.
Harry's epiphany, on the other hand, was that Hermione was
pretty, beautiful, different, delicious, snoggable...
I'm beginning to think that this may well be one of JKR's most brilliant pieces of misdirection or obfustication (sp?) so far. It is
RON who 'realizes' that Hermione is a girl--and people automatically assume that Harry made the same realization a moment later.
Keep in mind, however, that Harry already
knew what a 'girl' (in the gender-based, hormonally driven, snoggy-shaggy kind of way) was:
QUOTE
POA, Ch 13, 'Gryffindor vs Ravenclaw'
... The Ravenclaw team, dressed in blue, were already standing in the middle of the field. Their Seeker, Cho Chang, was the only girl on their team. She was shorter than Harry by about a head, and Harry couldn’t help noticing, nervous as he was, that she was extremely pretty. She smiled at Harry as the teams faced each other behind their captains, and he felt a slight lurch in the region of his stomach that he didn’t think had anything to do with nerves. (Underscoring Supplied)
In other words, Harry
knew that Hermione is a girl (and has always treated her as one) but he never really thought of her as a 'girly-girl' until the Yule Ball when... "His eyes fell instead on the girl next to Krum. His jaw dropped.
"It was Hermione."
Ron, on the other hand, never had a clue until his 'epiphany' in fourth year--and even then, I think he still thinks of Hermione in the same way that he sees Ginny: as a sister but not someone that he would date.
More importantly, Ron's actuations before, during and especially
after the Yule Ball has subtly shifted attention away from Harry's epiphany of Hermione as a 'pretty girl' towards Ron... and has seemingly blinded a lot of people towards thinking Ron/Hermione when the whole thing is, essentially, another step or building block of the H/Hr relationship.
Thank you for letting me ramble.
gil