Have you tried hugging her more and praising her more? And when you take away privileges, is it something (she likes badly enough) that will really cause her to stop her behavior? If you find that one thing that she can't do without (ex. computer time, t.v. time, etc.), then be consistent with it.
This is a tough situation, and I can tell you dearly love her. Have you tried putting her in taekwondo? My 9-yr. old son had a hard time focusing on his homework since 1st grade. I put him in taekwondo ("tkd") and it has helped him to focus some as well as be rewarded. He progresses to the next level every 2 months. And now he is a first degree, level 3 black belt. It has also taught him to listen and respect others. It's a good discipline tool. He focuses a lot more. Also, because he respects his tkd instructor so much, we used to say, "If 'Mr. N' saw you do that, do you think he would approve?" And he would straighten up. I really like what it teaches so I put 2 more of my children (8yr. old daughter and 6yr. old son) in the program and they will be black belts within 6 months (2-yr. commitment to black belt). If you put her in, she might want to quit in the middle (that happens a lot), but insist that she commit to 2 years ("once a black belt, always a black belt" - and what an achievement)!
Tkd is good for everyone, so if you put her in, consider doing it yourself with her. Some places have family sessions where adults and kids do it together. Good luck to you. Get together and set goals for her (achievement instead of material things might be a better reward)!