Me too, in primary school I had some serious bullies, there was some actual physical violence even. Not so much in high school, fortunately. But I believe in sympathizing with bullies as real, complex, and often quite normal people. And I'm a pacifist so I don't just attack people back, I believe there is usually a quite empathetic way to deal with things. It's just usually harder and less obvious.
No, that's not what I'm getting at. It's more like a) they don't really have it in them to commit something truly nasty; b) they realize that high school is just a phase; and c) they move beyond their past hurts to pursue their own hopes and dreams. Might be rather anticlimactic, for readers hoping to see a real payback tho. [ETA - it did just occur to me (while I was writing this post) that there could be a couple of paragraphs at the end that's set 20 years after graduation where the 3 meet again at their class reunion and all have very successful careers and happy family lives. Like a "living well is the best revenge" sort of thing.]
I like that you have incorporated several themes: sexuality, ambition and timidness. What I would do in my case is write each character story separately, and then weave them all together. The closet-lesbian would be the easiest, simply because there are a lot of themes and personal growths that you can cover with such a character, and your Queen-B can simply be the person who creates obstacles for that character's growth and development. The shy one could work through her anxieties, or be sensitive to certain things the crush says. I would add on top of that a deep-rooted fear for her. It would give you more to work with than simply "I am shy". Miss Harvard-Ambition could dedicate all her time to studying and trying to climb that educational ladder, but I would also add another layer to make it more interesting. Maybe she could have a deep sense of failure, or maybe everyone before her went to Harvard and if she doesn't get it, it would be humiliating for her. OR, she could have an inner struggle. SHe wants to get in to make her family proud, but she actually wants to pursue something entirely different and is unhappy but willing to conform. I think the more layers you add to your characters, the more you will have to work with in your story. Plus having it all happen in high school years gives you the advantage of sexual exploration, personal growth, family issues that arise, career choices, thinking about the future etc etc.
