If shes a junior, shes close to finishing high school. I hope she realizes she will br working at McDonalds or Burgerking if she does not finish.I have a daughter who is a sophmore and thank god she is self motivated. No fast food job for her. Talk to your daughter. I'll bet she does not want to end up at such a low end job. The job market is very tough without an education!  GOOD LUCK!

I would recommend that try to figure out her attitudes thoroughly; I hope you do understand her but teen years are hard to figure out completely. She has potential and you can help her out. The first step in keeping up to date with your kids is educating yourself on all the possibilities. Once you get the basic info and educate yourself a bit you need to implement that knowledge. See if your kid is falling under a certain category or if he shows symptoms of any troubling issue. When you are educated you are more likely to spot a problem when it’s starting, rather that noticing it too late when it’s already hard to deal with it.
Teens just have different attitudes and each one of them requires a different approach. Yes, there are those teens that will give you the lip, but there are teens that are just set in a certain way, either way they all need some push into the right direction. Well, more like guidance than a push, after all they simply do it because it soothes them in some way.
Best wishes for your daughter..

I am a firm believer that kids will NOT do as you tell them to do but they WILL do what you do.  In other words; LEAD BY EXAMPLE, and stay positive!  I think all people, especially teens, pick up on what's negative. If you are a hard worker they pick up on that.  If you are a nag and get all over them, they reject that....[Edited by Education.com Community Team]

Don't worry, it's not too late; I believe there are some things you can do to actually improve the situation. The first thing you can do is to forget withholding her ice cream and forget a reward plan; kids see right through that stuff and hate you for trying to manipulate them. Most of the time all those plans are too taxing on you so the plan gets forgotten anyway.  So what do you do? Well, believe it or not kids are motivated by fear. Yes, fear. Not fear for their life, (no mean stuff hear me), but fear of what their future will be, or fear of hard work.  

I some what agree with the guy that suggests taking her to McDonald's and showing her what her life will be, however, I don't actually suggest McDonalds, Fortune 500 magazine calls the McJobs the best way to start a stunning business career; why not learn from the best.  You should, however start her on a path of manual labor, now, while she is young, take away the allowance and tell her no dough till the grades improve, then, if she is 16 years old, set her on the working trail. Tell her no allowance but she can work if she wants to; at 16 there are plenty of terrible jobs out there to break her in right. A little networking on your part and you could get her a great job cleaning grease traps or similar work. I think one of two things will happen; she will learn to love grease, quit school and work full time, or, she will see the value in doing well in school.  

You see, you cannot motivate her, she has to motivate herself, your job is to manipulate circumstances to get the desired result; and by the way, she'll love you for it, you'll see.