I don't know what your daughter has, but I can sympathize with the sex issues. 70% of bipolars are hypersexual, so it is more likely to be an issue than not at/after puberty.
At some point, the best you can do is to provide lots of condoms and the reasons to use them---and lots of low-key information on why rampant promiscuity is not in one's own best interests.
We did have a case in our metro area of kids having orgies at each others' houses after school and before parents got home.
It's a "no go" but unfortunately the only even partial cure for it is lots of supervision.
And, of course, you need to find out if there's an underlying brain problem causing the promiscuity.
In bipolars (for example) you can at least improve impulse control by getting our moods stabilized. And improving impulse control may not decrease sex drive, but it at least interposes some rational thought between drive and decision.
*If* there's some kind of organic brain problem contributing to her bad judgement and bad impulse control, you need to treat that problem before you're going to get improved behavior.
A portion of it, and there's no telling what portion, is that teens are *all* a bit rash---poor impulse control---compared to what they were as kids and will be as adults.
Part of it, a large part, is that teens frontal lobes are still developing. Organically, they don't have adult brains yet, and all that will really help is time---and time *will* help. Guess where impulse control lives? The frontal lobes.
I know rampant promiscuity is dangerous, and I'd be scared as hell, too. My husband and I have thought about this quite a bit based on what I was like as a teen and based upon the range of possibilities we're likely to face when our daughter is a teen.
Adding PTSD on top of whatever your kid's other problems are won't help. If I were you I'd seriously consider moving her to a same-sex traditional boarding school that is *not* a boot camp but limits contact with the opposite sex.
I hate to be this blunt, but if some of the girls decide to do each other, while there's *morally* a problem, she'll grow out of it, and she isn't going to get HIV from another girl.
What you really need is to keep her alive and uninfected until she grows up a bit---and *possibly* to take care of any underlying psychiatric problem, if there is one. But the kicker is without doing further damage.
Or, you could bring her home, maybe move towns to get her away from that crowd (or move across town)---which is a hell of a hassle, but considering the alternatives, worth it. Then you could make sure she doesn't leave the house without condoms in her purse---not to go *anywhere*---and supervise her as closely as possible whenever you could.
The goal here wouldn't be to *stop* her having sex, but to reduce her opportunities for sex and make it as easy as possible, when she slips the leash and gives in to the impulse for sex, to happen to think, "what the hell, I've got a condom...." and actually use the thing.
Reduce the risk, and try to provide fun that doesn't include sex on the menu---swimming, running, hiking, biking, skating (ice or roller), sports, music and dance. Again, martial arts is good *if* she takes to it because it's a good "fix" for an adrenaline junkie---if she's getting off on the thrill, and you can get her to get some of that thrill from sparring, you've got a *healthy* outlet. The other thing you might think about is other adrenaline-generating kinds of sports or recreation---roller coasters, hang gliding, bungee jumping, rappelling, competitive diving. If you can get her into running and hooked on "runner's high" it's safer than rampant promiscuity. Scuba diving, maybe. Rock climbing.
If you can get any organic brain problem stabilized, and divert her into a less self-destructive "kick," you might be able to at least reduce the risk.
If you end up with a psychiatrist helping you, and a therapist, maybe the therapist can persuade her to at least *try* different adventure sports, one after another. You may want to try them with her, or somehow arrange for a girlfriend to go along.
If you pick the sports that are higher in the number of boys that participate, you might get her to go along, thinking she's fooling you, in the hope of meeting cute boys with great bods----but then if she ends up into the sport to impress the guy, she's getting a less self-destructive high even if she does end up having a sexual relationship with a boyfriend. I get the impression that at this point *one* boyfriend and *safe* sex would be a relief.
I know this sounds like rewarding her for bad behavior, but if you're doing these things as a family, you can present them as rebuilding family time---and bring a girlfriend and let them flirt with the guys (because it lets her feel like she's getting around you a bit, you're more likely to get her buy-in--while reducing risk).
With a difficult kid, sometimes it's not so much about reward or punishment---that's a cycle you can get locked into that can get destructive. A lot of times it's about "distract and divert." You see what the kid's drives are, and you subtly (okay, even sneakily) divert her into ways of expressing those drives that are less self-destructive and healthier.
I think that's why the *original* Outward Bound actually worked/works for some kids---its orientation wasn't punitive, it was diversionary---divert the kid's drives and adrenaline-seeking into a constructive pursuit.
Hell, get the family roller-blading and hire a cute roller-blade instructor, or go on ski trips and get a ski instructor with the body of a pagan god. Get her places where there's a non-sex adrenaline fix on the "table." Get her places where the cutest guys around are getting *their* adrenaline fix from the sport and won't be impressed by promiscuity. Give her proximity to cute guys with healthy self-respect that she'll want to impress.
And then, of course, when you find an adrenaline sport she loves, stick with it. And stick with it with you and her dad going out and doing it, too--just not smothering her with your closeness while doing it.
That's what I'd do if my own daughter, as a teen, was behaving like you describe.
You could even be sneakier---I don't know if this would be a plus or a minus---and go into family therapy with the therapist primed beforehand where the therapist talks the seemingly-reluctant parents into taking their daughter on these family sport-adventure trips. It's sneaky, and it's underhanded, and if you get caught you're screwed---and I don't know if you can act worth beans. But if your kid is seriously oppositional, being talked into it by the family therapist who's "on your daughter's side" might make her more open to going and doing.
You can't get a teen to *not* seek thrills. Not without severely damaging her.
What you *can* do is channel her towards thrills with some real risk, and some risk that's just apparent, but a *much lower* real risk than her current bad behavior.
Timoclea