The only way a Female badge collwctoe could work if she and her team got 4-5 badges and the last GL destroyed her so she doesn't want to fight again. so after Ash defeats that GL she rechallenges and wins. get s her mojo back and collects the last few badges. but she will have already 2-3 from the last ones so she fights X2,Y2 or Z new gym.
BUT THAT WILL BE A HUGE . . .
I would love Bianca as the female lead but with a new goal. and if not and the XY girl comes I don't see her doing battling. more something like fashion or so. . .