My mom said the same thing about me.. but then again, I never had much of a problem with who I was before I hit puberty. It was when the boys and the girls really started to separate and diverge from one another that I started to have real problems.
I have a ten year old daughter who doesn't like dolls that much, and hates the color pink.
So yeah, it doesn't matter whether or not we did anything especially "girly" when we were children. I just consider myself the typical "tomboy"... except, I really happened to be a boy, physically. If natal girls can be tomboys, then we can too :-)