Modesty is a super-huge deal in fundamentalist sectors. It's a shame that fundamentalist efforts toward modesty are quite often self-defeating - superficially "solving" one problem while creating another.
Let's take a minute to consider the whole frumpy, long hair and denim jumpers thing. It's a path chosen by those who consider sexuality to be the greatest factor in or element of modesty. I've always immediately pegged anyone wearing the long hair/denim jumper combo as some form of Pentecostal, some form of Holiness, et cetera. I didn't know it was the norm in the Christian homeschooling world, too, until a couple of years back, because, frankly, I knew next to nothing about the Christian homeschooling world until a couple of years back.
Here's the problem...
While fundamentalist Christians may consider the long hair/denim jumper (or super long skirt) deal modest, I have another name for it: a uniform. A fundamentalist Christianity uniform. It makes it easy for people to peg you, immediately, as a fundamentalist Christian - for all the wrong reasons. I'm pretty sure Jesus never said "...and they will know you by your Christian uniform." The self-defeat really kicks in, though, in that modesty, at its core, means to NOT draw attention to yourself, especially in superficial manner...and it's kinda hard not to stand out like a sore thumb in the frump of a denim jumper. It isn't exactly the clothing choice of atheists, or agnostics, or even mainstream evangelicals (you know, those people who fundamentalists don't believe are "real" Christians). The ONLY people wearing it are fundamentalists, which makes it a sure-fire attention-getter, which means a big ole oopsy daisy on the whole idea of modesty.
I agree with people who say "modesty is a matter of the heart". But...if you start putting on a modesty uniform, then, well, not so much. If someone really wants to "lust after" you, they're gonna. That's on them. Not on you. Lust, just like modesty, is a "matter of the heart" that no uniform will conquer.