You should be commended for seeking help and guidance with disciplining your daughter!  One of the first things that you may want to do is to make a list of her problem behaviors, getting input from your fiancé on this as well.  What does she do that you don€™t like, what things set her off?  Does she have a hard time following instructions/rules, accepting €œno€" answers, accepting your feedback or consequences?  
You may want to take a teaching approach with her rather than a punishing one.  Often times kids react to things they don€™t like with angry outbursts because they haven€™t been taught the appropriate way to handle things. There are some very basic social skills that you may want to consider teaching her:
Following Instructions
1. Look at the person  (if she is looking at you, she is more likely paying attention)
2. Say OK (she may want to argue or complain, but OK is all you want to hear)
3. Do what is asked (she needs to either do it right away, or at the time you set for her to do it)
Accepting a No Answer/Consequences/Feedback
1. Look at the person
2. Say OK
3. If you have a concern, calmly bring it up 15 minutes later

In addition to teaching her how you want her to respond, assess if there are €œhouse rules€" that you can set up that relate to problem behaviors.  Sometimes it is just a matter of structuring the day, such as:
1. Bedtime for school nights, and weekends
2. A daily chore that you want her to do & when it needs to be done
3. Amount of time she can spend daily on the TV or Computer.

Then you should come up with a list of consequences that you can use that you think will be effective, and that you will be able to administer.  It is also very important that you don€™t react in anger.  Effective consequences are those that €œteach€" not €œpunish.€"  You will then need to be consistent with your monitoring of her behavior.

Also, as you make a list of her problem behaviors, you and your fiancé should make a list of her good points as well.  This will help you to focus on positives, and you can then praise her when she behaves the way you want.  

It is great that you are starting to work with a counselor especially now that you are getting married. Be sure to be open in discussing these things with your daughter.  Let her know that you want to help her and to be successful at home, school and in the future!
Boys Town National Hotline an Education.com partner
€“ 1-800-448-3000 / www.boystown.org

my two sons went to a Christian high school their last 3 yrs. of high school and they loved it. they told me they learned more and that the teachers did not have such a large number of students and they took more time with them than the public schools. there is alot of bullying in public schools , students dont have to put up with in a Christian schools. so i think i would continue sending him to a Christian school. good idea would be to ask him where he would rather go. he knows alot more about what is happenig in school than you may not be waare of.

You daughter is going through some sort of behavior problems, and in her tween years, scolding or limiting access to certain things won't do any good. She is now old enough to know her behaviors, but the main problem is you can't motivate her not to do such things that you don't like, even if you try to enforce, tweens or teens get rebellious. I would like to quote few informative lines from a reputable home based intervention program. " No Parenting technique, approach, talk, or change on your part will work until your child is motivated to listen to and follow your directions. Most children don't lack the ability to obey their parents or follow rules, they simply lack the motivation to do so."
So I would recommend you try a home based intervention using any reputable program available on like the total transformation or home intervention system. The Home Intervention System was developed by administrators of schools and programs for struggling youth and has been adapted for home use. The Home Intervention System shows you how to motivate your teen to make changes just like they do in these schools and programs. The System utilizes a simple but powerful Attitude and Behavior Modification Program.
The Home Intervention System will help you deal with a wide range of problems that children often encounter including; anger, substance abuse, school issues, self-esteem, arguing, motivation, interacting with family, and more.
Parents, teachers, school counselors, grandparents, and any other individuals who frequently interact with children will benefit from techniques and concepts presented by the Home Intervention System.
I hope this program helps you and guide you step by step how to change her behaviors, but you can also go for counseling or to a specialist that can intervene into it in modifying her behaviors.
Best wishes...