I admit that my preferences and my most wanteds aren't female characters, but I definitely think there are a good variety of options for a female newcomer. Not the same amount in comparison to male characters because I'd say the majority of iconic characters are male (I mean, most protagonists in gaming are men or some kind of mascot).
One of my top picks would be Amaterasu from Okami. I don't think she has a real chance for two reasons: the absurd amount of competition she faces with other Capcom franchises, and that Okami as a franchise is almost dead at this day. I could see her as a base roster adittion, that way maybe she could happen. But I would be really happy if Amaterasu makes it into Smash.
Also I would love Jill. As I said in other threads I can't pretend I prefer her over Leon, but at the same time it would feel a bit wrong to me to include Leon but no Jill and viceversa. The problem is, at least with fighter 5, we won't have new echo fighters. Yeah they could make like Hero and include Jill and Leon in the same slot, but to me the right way for these characters is to have their own slot, like Simon and Richter.
Then there's 2B. Nier Automata was one of my favourite games of 2017 and I loved that game. I honestly don't think 2B has great chances for a similar reason to Amaterasu, she has strong competition and we just had Hero from Square, so I don't know. I think she would be like Joker, an ideal character to open the next fighter pass. It would confuse people in a good way and she would be unexpected.
Also there's Shantae, Lara... I didn't play their games, but I would be okay with both, specially Lara. I have the feeling the actual Lara hasn't the same status as the classic Lara, but her inclusion would be a big thing, specially if Sakurai goes with an updated classic design. Chun Li is another option but I doubt we will get 3 SF characters and honestly, despite she being really iconic, I'd prefer representation for another Capcom franchise.
I hope for some female representation. I think we will definitely have at least one female character, but I feel we will get more than one. I didn't talk about first party because I don't think they have great chances but if we include first party characters, Dixie Kong and Lyn are some of my most wanted!