If they were desperately looking for warrior queens, Zenobia would have been a much stronger choice. They gave in to ethno-centrism and some kind of political populism/correctness when including her and the Celts for that matter. It probably sells to a certain market and no doubt there were some requests. It wasn't the first time they did that and it likely will not be the last.
You and I both know that the majority of the female leaders in the game are there because of an attempt at gender balance. Lizzie, Catherine, and perhaps Victoria might belong there for their contributions, but any others would be there to fill a gap. The problem with adding any sort of female leader, is that there are very few of them in history that actually did anything really significant in their own right, or if they did, there are very few of them to pick from.
Face it, it's been a man's world for most of our history. There have been some women that have stood out in our history, but most wouldn't qualify as they haven't ruled a country/empire, whatever, so the question is pretty much moot.
Firaxis gave us the women that they gave us, and there isn't much to do about it but mod in the ones we want to have in the game. There have been a number of nerd wars about this in the past in the threads, but it all boils down to the fact that the game designers were trying to balance out the testosterone a little, and maybe be partly PC in the process. They probably did get a little ethnocentric. There are more leaders per civ in the civs that represent where the game sells better. It's marketing, like everything else in today's culture of Advertising/Technology/Celebrity worship. Who cares?
Would I like more women in the game? Yes, I would, but I would like them to be qualified to be there. Beyond that, they are just pixels like the rest of the leaders in the game, and I'm more concerned with how my hair looks right now than I am with historical justifications on which leader gets to be in the game.
It's just a game.