I agree with simply being honest. Unfortunately, you can't always be sure who will accept it and who won't. Even if the initial reaction doesn't seem to quite be acceptance (but isn't unacceptance), give people a chance to "absorb" the information. Some people may not have had someone come out to them before, and aren't sure how to react. They might be ok with a gay person, but don't expect it to be someone they may have thought of as straight all the time they've known her. It might be something new. I'm just saying this, in case you get a reaction that doesn't seem to fall in either category of acceptance or non-acceptance.