There is only one fool-proof method. You ask them.
If she eats pussy...she is a lesbian (or bisexual).
the term Lesbian is generally reserved for humans. Most gerbils are capable of exhibiting bisexual behavior.
Lesbian? NO. Bisexual? YES!
No. Bisexual, gay, and lesbian are sexual orientations, not genders.
Gay and Lesbian means someone who is attracted to the same sex. Bi is short for Bisexual, someone who is attracted to both sexes equally.
A bi lesbian typically refers to a woman who identifies as both bisexual and lesbian. This can mean that she is attracted to multiple genders, but primarily or exclusively to women. It's important to respect individuals' self-identified labels and how they choose to define their own sexual orientation.
Bisexual
If you are attracted to women after being attracted to a man, then you are most likely bisexual, not a lesbian.
You don't know whether you are gay, straight, lesbian or bisexual.
There are almost 3,000 FAQ about Gay, Lesbian and Bisexual on WikiAnswers.
'I'm bisexual'
A bisexual is someone who is physically, sexualy and emotionaly attracted to both boys and girls. There is no real way to tell if your girlfriend is into you. If your girlfriend is not kissing you or doing sexual things with you, it doesn't mean she is not interested, it could mean that she is shy, or has insicurity or a personality disorder. Try talking to her. If she isn't a lesbian or bisexual then she usually wouldn't be dating you.