It is incorrect to call oneself Asexual and Lesbian because, as you've stated, that is contradictory. It would be more apt to call her homo-romantic, or something like that. An asexual is perfectly capable of finding others physically attractive and developing romantic feelings. Some don't, of course. The only thing we lack is a desire to engage in sexual activity. For some it is a dull chore, for others it is absolutely revolting.
I agree that the constant addition of new terms can be a bit frustrating, but I am glad this particular sexuality is becoming a bit more well-known. I grew up under the assumption that I was bisexual because I found men and women equally attractive. That being not at all. Then I discovered people want to engage in sexual activities and hug and kiss. I always assumed everyone else thought it was disgusting too, but no. People look at one another and have a desire to mate. They find sex-organs appealing. They wish to spend day after day with someone who regularly invades their personal space. When I finally read about asexuality, I no longer felt as though I were some callous alien incapable of basic human desires.