Needs to be a person first. Plain and simple. Dunno if she counts since she’s a silent protagonist in the game she actually does lead, but Maya Amano is still one of my favorite gaming heroines. She is central to the plot, her personality is so lovable and positive, and yet she has flaws and vulnerabilities that really have nothing to do with being a woman or being victimized. Same goes for Aqua from Kingdom Hearts - she the smartest person in the group, spending most of her story fixing what the others messed up, but there’s no sexist message behind it.

Basically, I think I like female heroes for the same reasons I like male heroes and, in general, I think that if you can switch the gender and it still works, you’re doing something good with your character. Heck, despite how polarizing she is, I think even Lightning is a good heroine if only because I have no problem imagining her as a man as it would really not impact the story at all. And I don’t mean heroines shouldn’t be feminine - all of my three examples are very overtly feminine without going too stereotypical or oversexualizing them.