^^^ I like your theory. We are nice, aren't we?
Sorors NinjaPoodle and TRSimon gave advice that I'd second. If you're already an out lesbian as you said, then at least the ladies in the chapter already know who you are. Just don't beat people over the head with, "I'm a lesbian! I'm a lesbian!"
Can they get to know YOU, not your orientation? If you have a good character and reputation, then maybe the enlightened membership can see past your orientation and just see you as a quality prospect. Everyone isn't enlightened, and you know that based on everyday life. Just be careful, and be yourself. Remember, if it doesn't happen during college, you may continue to pursue membership on the alumnae level. Good luck.