Here is an interesting link:
http://www.medhelp.org/posts/Child-Behavior/7-year-old-da...
its about a different aged girl and her tantrums, but it basically is about a child that acts out... when not getting her way and she has inappropriate reactions.
Now... does your daughter act this way ANYWHERE, anyplace... or just at home or with you? If it is only happening at home or with you and at school she is fine... then it is a situational thing perhaps... versus a "clinical" problem. Because if she had a clinical problem, it would be happening anywhere... not just at home.
Also, you may look into if certain foods affects her moods. Hypoglycemia for example makes kids edgy. Or they are sensitive to certain foods and it affects them.
But if it is a relationship dynamic & problem... then take a look at the home dynamics... and interrelationships there. AND of course, YOUR relationship with her. AND it will take EVERYONE to comply... with improving the atmosphere. ie: if EVERYONE in the house is "defensive & stubborn" as you said... well, this can REALLY REALLY negatively affect a child and their happiness. So, that may HAVE To be corrected... because it is affecting her OVERALL well-being.... and no child can cope when their household is just not a positive place. Maybe she is thus... always on edge... because of it. REALLY take a look at that. It is not just HER... but her as a RESULT OF the overall dynamics in the home and the usual "defensive & Stubborn" reactions of the family members. It is stressful I am sure, being around that kind of atmosphere I am sure... and she is reacting to it. Imagine being in an office where the boss and all the employees were all "defensive & stubborn"... WOULD YOU be happy there and nice and pleasant feeling? No. It would cause stress/unhappiness/irritability etc. And some employees may even quit or that company would have a HIGH turn-over rate.
So... for a young child being in an atmosphere like that, at home... I can imagine it being real hard for her. She is just trying to "COPE"...
Some kids...are VERY sensitive and deeply affected by the negative personalities/dynamics of their family members... especially if they are always "defensive & stubborn."
To me, she is just replicating that... and doing the SAME thing.
** A CHILD cannot become better... if what is going on at home is not better. They CANNOT act alone. They are only becoming or copying what is going on at home... or acting out of frustration. A CHILD cannot "fix" everything. The "Parent" has to lead... they are the "Leader" in the family...
Perhaps she takes it out on you... because she feels closest to you and safest. OFTEN times, a person will take out their frustrations on the closest person to them. So it is a double-edged sword.
YOu really have to get her disciplined etc. But you already know that, as most Moms do.
Here is a link:
http://life.familyeducation.com/discipline/parenting/2945...
There is also a GREAT book called: "How To Talk So Kids Will Listen, and Listen So Kids Will Talk." Which you can find on www.amazon.com
Its a great book. I recommend it.
It may also be that "emotionally" she is not mature yet, in comparison with her numeric "age." So, perhaps teaching her "COPING SKILLS" can help... to learn alternate & acceptable ways of behaving... while at the same time being ALLOWED to express herself. Lots of times too... a child needs Validation... actually acknowledging them even though they are feeling negative... but then redirecting them as well. ie: "I know you are upset and feel irked... so can you tell me why? I want to help you... if I don't understand, can you tell me so I know how you feel?" Then talk about it... openly without judgment or scolding.
If also a child is constantly getting scolded... they sort of just snap all the time. Its too much "pressure" to be acting "perfect" ALL the time. So how can she feel better about that AND herself? Does she perhaps feel junk about herself... and so she takes it out on others? This happens even with adults. Self-esteem... how is hers?
Don't "argue" with her. Tell her "I will not argue with you...I am your Mommy...I love you..." Then don't engage until she can calm down.
Just some ideas, I know it is not easy.
All the best,
Susan