I'm not a sexologist, but what your mother said is a load of crap, no offense to your mother. Being a lesbian is about being romantically attracted to women, end of discussion. Even if you never have sex with one, you are still a lesbian.
By: Lewandowsky
+135reps
nice
By: Sottosanti
+202reps
Also, any reason not to date someone is valid. Just because it's such a personal connection.