Nanny- in every seminary there will be girls struggling with certain issues.
For example, even in the most frum schools, there will be girls struggling with movies, non-Jewish music etc. The thing is in those schools, the girls will try to cover it up. On the other hand, in some schools, where it's more accepted, girls may be more open about their "activities." Keep that in mind.
Also, e/o struggles. So no matter what sem u go to, there will be girls struggling with at least a few issues. In some BY seminaries, the struggles may not be the same as in non-BYs, but keep in mind that there are issues e/w.
Unfortunately, the world isn't perfect, there is no perfect school or perfect person. But you should choose a school most suited to you and your goals. (Remember, no one has a destiny, Hashem is in charge!)
Do your best, apply to where you see yourself going and Hashem will help you get accepted where you need to go and ultimately, help you decide where you are going.
(Nanny-I think I know you.)