My dear, wanting characters just because they are female isn't the entire point. They too must have the legacy of gaming to fulfill. There are a handful out there, but they too are worthy of recognition just like the males. Wanting females just because of their gender is the minimum but "not enough" requirement to be a viable candidate.
There are plenty of viable choices out there. It's just that wanting female isn't enough of a good requirement to be viable. Anyone can get in, as they say, but only if they can bring something new to the table other than being female.
Let's say my most wanted, Morrigan Aensland from Darkstalkers. She's female, has been part of Capcom's roster of crossover characters, and has an interesting thing going for her that differentiates her from the other Shotoclones we have in the game. Maybe her playstyle won't even revolve too much on her fighting game roots, but its up for the devs to design her moveset honestly.
Or KOS-MOS, the most viable female rep so har. She's female, has been a part of Bamco's crossover roster, is also a robot (a niche fulfilled by ROB and Mega Man), and has a crapton of weapons she can use, though she's mostly associated with her long ranged firearms. She could be a great zoner and a decent markswoman.
In general, there are many viable female reps, and they too have many things they can bring to the table.