I'm not sure about the traditional fairy tales, but if you want a fairy tale vibe with powerful well-written female characters, try The Enchanted Forest Chronicles. Seven might be a little young for reading them on her own, but they would be excellent for reading out loud to her. Or just wait a few years and give them to her around fourth or fifth grade.
Oh man, I loved the Enchanted Forest Chronicles as a kid. I can't wait to share them if I ever have kids of my own.
It's a wonderful mix of humor and fantasy, and it's one of the things that got me hooked on the genre as a little kid.
The Redwall series is also great (though I don't remember how many follow a female main character), but some of the books get a little more mature and should probably wait until she's a little older.
I don't think so...If you read the intro to the updated version, it talks about the dynamics of it & how she basically backed into the first three books due to the little bit of history she included in the fourth. Look at the preview here -- it's super interesting!