Which leads to Fridge Horror as Massie's an implied sociopath, and probably won't get retribution for a good long time.
This series actually kind of works if you take it as an over-the-top Stealth Parody.
It also works if you see it as mildly depressing Truth in Television: Girls like the The Clique really do exist, and they almost never learn anything or suffer the consquences of what they've done (at least not until much later in life).
All those older guys who are constantly mentioned as "checking out" the Pretty Committee probably aren't ephebophiles. In reality, they're likely smiling in amusement at a bunch of middle school-aged girls who probably look ridiculous dressing and acting like women in their twenties—the PC-girls just take it in a sexual way because they think they're "all that." It may not be what the author was going for, but it certainly makes it easier to read.
The books, particularly the later ones, make it clear that Briarwood doesn't have uniforms. The Movie puts the Briarwood boys in formal school blazers and ties. They were probably setting things up so the girls' uniform design contest could be part of the school merger so that they could've gotten on with that plot without having to show 12-year-old girls in offensively Stripperiffic Halloween costumes.
What kind of teasing did Olivia get about her nose that made her feel like she had to change it at 12 years old?
It's implied that Alicia has breast implants at TWELVE. What kind of parent would allow that?.
Or worse, encourage it?
If I recall correctly, it's mentioned at a few points that she doesn't even want them. Only her parents did.
Bit of extra FH as to why they'd force their preteen daughter to get them. There isn't one possible answer to that question that isn't full of squick.
What reputable doctor would even do that, and what kind of disreputable doctor did it?!
Maybe not the only one? If I recall, Massie comments at one point that "(this or that problem) is as bad as when her implants burst".
At age 12, girls are starting to go through puberty and naturally, breasts tend to be an area of concern for them. It could be that Alicia's parents, being image/material obsessed (her mom is a supermodel, for heaven's sakes) thought that getting their daughter implants was actually helping her avoid body image problems in the future, and allow her to maintain a "superhumanly attractive" appearance. The fact that she would have resulting body image problems FROM the breasts should have been obvious, but to parents who allow their children to get up to the antics that Alicia and Massie do, perhaps not so much.
Alicia trusts absolutely nobody, all she wants is to be the is center of attention, what's going to happen to her when she enters the real world? Hell, even high school?
Her cousin Nina probably won't fare much better—she's only a year older than Alicia and the rest of the Pretty Committee, but yet she has D-cups, dresses/acts like she's 25, and is heavily implied to be sexually active. She's a sexual predator's dream come true.
In the book where all of the PC go to Hollywood, there's talk of a star who may like Claire, and who also is "hooking up" with another female lead. Claire is 12, and the other two can't be much older or the gossip columns would be mentioning a significant age difference. Still, even if the two stars are 15, that's very young to be hooking up so casually, and way too old for Claire. This is the kind of thing I bought when I was 11, but now it's just Squicky. Also, in one of the one-clique-member vacation books, Alicia and her cousins are in Spain, and a bouncer lets her and her cousins in because he thinks they're hot. Alicia is 12, one of her cousins is 13 (and described in earlier books to dress like a 25-year-old and have D-cups) and the other two are 15. Great, now we've got full out ephebophilia (and this was something even 11-year-old me thought was gross).
Also Fridge Brilliance (should this go below?): The age of consent in Spain was 13. Make of that what you will.
Considering the insane amount of knowledge that the Clique girls have of makeup techniques and the latest fashions, it would probably not be immediately apparent that they were so young. Maybe the bouncer thought they were hot older teens who happened to be short.
Speaking as another someone who's middle/high years were when these books were created, in this troper's middle school experience the sexuality bits here would be rather a shock. Most kids my age, lost their v-cards in high school in their 15-18 ranges, not their 12-14. But by the time we we're graduating it was becoming far more common knowledge in our schools middle school kids were experimenting much faster than we ever did. You may Squick away now.
You forgot the main horror here, folks. GIRLS LIKE THIS EXIST IN REAL LIFE.