D.L.
The more you fuss the more attitude she'll give. She is most likely experimenting with how far she can go beyond her childhood boundaries. Unfortunatly taking away privleges ususally only works for that moment. The most effective way that I've experienced is when she starts giving attitude, is to simply reply "I'm really sorry you are having a bad moment right now. Is there anything you'd like to talk about, or that I can do to help you." More than likely you'll get a "NO" answer. Ask her if she's sure there's nothing to talk about, and if she still says no, let it go until later in the day. Perhaps in the evening before she goes to sleep, you can try asking her again. She's never too old for that few moments at bedtime to let her know you love her and that you want to help her with anything she's worried about. They are all "little girls" at heart, even when they try to say they aren't.
Most importantly-- check yourself to make sure you are not giving her "attitude" either. It's very easy to pick up on their attitude, and use a mocking tone. Don't fall into that, it just makes things worse. Good luck and let me know how its going.