Many websites are zombie games, cars, motorcycles, all boy things. It was hard for me to find good websites that girls would find interesting. After searching everywhere, this is what I found.
Girl Sense: www.girlsense.com This website is a great site to go to if you love fashion and designing clothes. You own your own clothing label, get to design a boutique, advertise your boutique, design clothes, and sell your clothing at your price to other Girl Sense users. The registration is quick and easy, and it's pretty fun to do.
Games 2 Girls: www.games2girls.com This website has dress up, cooking, make up, music, every sort of game you could think of. This one is one of my absolute favorite websites to go to, there is so much to do. Games 2 Girls has games from tons of different websites, so it's easy to get what you want without switching pages again and again.
Girls Go Games: www.ggg.com This site is almost the same as Games 2 Girls, but you can register and you can be more specific about the games that you would like to play. I am not registered because it asks for your first and last name, and that is where I usually put up the red light because I would not give away personal information like that. It doesn't make a difference if you're registered or not.
Stardoll: www.stardoll.com This website is a fashion gaming website. You can dress up different celebrities, do their make up, stuff like that. The register is safe, and really easy to do. You create you own "Me Doll" and you can customize your suite, buy clothes, create albums, and buy clothes and make up. To get the full experience, you have to become a "Superstar". You pay monthly for it, but you shouldn't become a Superstar unless you will use the website a lot.