Good question! I have a few answers to this which really just stem down to the fact that that's what I wanted to do.
It does have something to do with me always finding myself playing as female characters in games when I had the opportunity - but also kinda wanting to see a female character up in the ranks of the Gokus and Narutos and Luffys etc. It also sorta originated from the fact that I always wanted to see a female super saiyan kick some ass since the end of Z but we never got to see it, and GT shafted those opportunities big time. So yeah, there wasn't a ton of thought behind it, just felt like the obvious thing for me to do