Do you consider this strange?

my older sister hasn't liked any body since she was around 11 years old (she's 20 now). the guy was older than her and didn't find any interest in her and just thought of her as a friend. i'm pretty sure she is telling me the truth; i just think it's so strange that she finds no attraction in guys. when we watch chick flicks together she kinda likes what she is watching and then drops it completely after the movie is done. is that asexual or what?