Little kids tend to make assumptions.
Especially since when you go to skate rental you automatically get figure skates for girls and hockey skates for boys unless you specify. Or at least that has been the case every time I've ever gone.
I learned to skate in hockey skates but prefer figure skates if I haven't been on the ice in a while. When I entered in formal skating lessons years ago I actually was told they would prefer me to wear figure skates since most girls in the group wore them and it changed how they taught things. My father was a hockey player for close to 30 years and I'm not sure he has completely forgiven me for switching to the dark side
I couldn't care less what skates people wear; I just think it is a little more conditioned for people to assume girls wear figure skates. Maybe things have changed since the days I was in lessons.