The only way she will ever know is tell her. And if you are afraid she doesnt go that way slowly ease your way into something like ask her what she thinks about A couple she knows about. If shes ok with them ease your way into how she would think of A lesdian or bi relationship if she frowns on it say no more and just keep her as A friend if she ok's it make your moove but make sure before you take the chance of ******* her off.
Have quite a few drinks, then when both drunk make out with her, tape the two of you if things get kinky and send it to me.....then we all win lolz :P
You might want to have a little more tact but i like my idea :P
I can't answer that one I'm straight.
I am straight but will tell you the same as 1woody, ask questions that will give you insight into her thoughts and feelings about lesbians.