Hi there.

Good question!
I think it's very, very common for women to notice and appreciate other women in a "beautiful/admiration sense" with or without being bisexual or anything. I think men do the same more in comparison (women do that too though), but they're not as liking to say it aloud.
I've always been attracted to what I call a "natural beauty" but am not bisexual. It confused me when I was a young woman. Now I realize that I wasn't attracted to that sexually, but I was attracted the that type of beauty. For instance, some are more attracted to a specific art style, etc. I wasn't attracted to the woman but the the type of beauty she showed. Am I making any sense? LOL.
Also, I admire in women and am attracted to that which I've always longed for...pretty hair. But that's getting off track...
I think what you've described is very common, and if it's only that statement that's made you wonder about yourself, I would stop wondering. Your time will come when you and life are ready to meet where you'll more than likely know exactly what it is you're attracted to.

However, if this is something you've always wondered about somewhere, you may want to explore yourself more on this.
KD