Up until now, female characters in Grand Theft Auto's universe have either been used for comedic relief (Catalina, Mallorie Bardas-Bellic etc) or as eye candy (Mercedes Cortez, Candy Suxxx and the various girlfriends available throughout the series). That's about to change once GTA 6 is released.
For the first time ever, Rockstar seem prepared to develop a serious female protagonist who doesn't rely on bitchy behaviour or sex appeal to become an important part of the story. It'll be interesting to see just how much the game's writers are able to resist old habits with this one.
That'll become even more true if GTA 6 does feature a solo protagonist. The childish scripting of female characters in the past makes it difficult to see Rockstar sticking to a new found moral code that casts this lead female as inspiring.
After all, Grand Theft Auto is about assuming the role of a despicable criminal, so it's a risky move if the writers aren't willing to throw in some humour here and there. Still, a playable female is long overdue for a franchise typically focused on male aggression.