She has a boy friend. Just because you had a dream does not make you a lesbian. If she ever lets you know that she is interested in you, then approach her with her feelings. If you persue this and she is not interested, you may lose her as a best friend forever. Remember she has a boyfriend, so unless she tells you she is interested, she is not a lesbian.Get over this or you may lose your friend. Remember we all have crazy dreams. Maybe you are watching too much of the wrong television.
Remember always that if you pursue this you could lose your best friend. Because of a crazy dream are you goiing to take that chance.