I feel my issue with Lightning is that she doesn't really break too much ground in terms of her character type. There are lots of grisly badass women who reveal a more nurturing side to soften their hard exterior in media. I mean in hindsight, she's a gruffer updated version of Faris without the drag. Both are no nonsense badasses but they have a softer side that is guided by their love of a sibling. The difference is that Faris didn't have to learn to be a better person. I also feel a different character before her (like the game that came before XIII) pulled the whole selfish character learns to look past themselves and be a better person trip just a little better.

I feel for me, I would go for someone like Lady Ashe and it's mainly because she has two important character traits: she's not afraid to get her hands dirty and she sees the bigger picture. With many RPGs falling into typical anime tropes, it was refreshing to see a character who actually put aside their personal desires because they could see the bigger picture at stake and understand that their desire doesn't actually align with what's best for others. Granted a lot of this is due to the fact that her desire wasn't exactly the nicest thing, but the genre is often overcrowded with conflicts that wind up not being a real issue as the personal desire actually does line up with the bigger picture of saving the world or whatnot. So I feel it was great to have a character who is not exactly the nicest person grow into the role she was born to be.

Overall, I feel one issue I'm seeing in this thread is people getting too stuck on the ''female'' part of the question. Yes, you may interpret is as who is a good role model for females, or you could see it as who is a good role model who happens to be a female. A role model is simply someone who has admirable traits that inspire others to follow in their path so I feel the question is more subjective than anything.