I am running the risk of being flamed. I have two children. One is a dream, never asks for anything, happy with everything he gets. The other one, asks for stuff all the time. Is not always grateful with what she receives and generally can be a real pain in the butt. My two kids have grown up with the same parents in the same enviroment but still they are completely different. My PITB child can also be the most giving child in the world, she always thinks about others and is always the one who thinks to buy me a gift. Something my first born never thinks about.
What I see in the OP a child who is craving attention. Any kind of attention however negatively. I don't know the situation but I wonder if she is getting much attention from her Mom. Does she have ADD? All of these things can compound into negative behavior esp. someplace like a mall. Does that mean you should never take her to the mall? No, real life happens and sometimes the family has to do things. Should she be allowed to change your trip to the MOA. No, things are going to be a certain way and at 12 she doesn't get to rule the family.
I think that she's trying to test you. She is so insecure about your love, that she is testing you. Don't fall for it. Be firm but very loving. She wants you to love her. She really does. She just doesn't know how. Maybe her Mom is too busy for her and negative attention is all that she can get, so that what she is trying on you.
Some of this behavior is typically for preteens. They really love to test you. They want to know how far they can go. It will drive you crazy but it ends (I hope!).
This is just my personal opinion but I hope that you will think about it.