Don't forget 18.

I think it's the blonde hair…

I mean, you still have to admit that female fighters in Dragon Ball (Until Super came along and introduced a bunch of them) were not only very few, but were also extremely side-lined. Let's do a quick inventory, shall we?:

Chichi: Fought once in Dragon Ball, lost, become housewife.
Videl: Fought once against Spopovitch, get utterly trashed, become housewife.
C-18: The only DBZ female fighter who actually mattered. Had one really cool fight against Vegeta that she won, making her one of the very few female character not introduced in Super to actually won a fight. Still became an housewife but still fight in Super, so that's okay.

I won't count OVA one-shot characters like Fasha or Zangya since they were extremely minor characters who died pretty quickly anyways.

You see where I'm getting at? Ironically enough, the most important female character in the entire series (who never become irrelevant as the show goes on) is actually a non-figther, Bulma. And that's probably because she is the oldest character with Goku, making her somewhat of a franchise mascot.