My mother always had a saying. "You do what I want, and then I'll do what you want." It really instilled a sense of equity in me, in the sense that I don't expect people to just do for me without doing something for them in return.
In this instance the OP has not once said to the child that she can't go. She's said, "you do what I want (put away the ironing board, which was only out to iron the child's clothes, so in effect was something the child wanted) and then I will do what you want (take you to the disco).
The ball is now in the child's court. But why should the mother "cut her slack"? This is not a two year old who doesn't understand bargaining and give-and-take. This is an eleven year old who is trying it on.
For everyone saying, "oh, she's a bit emotional because end of school", she'll have end of high school and God willing, end of university to feel this way again. Is the OP supposed to play punching bag for her again then?
For everyone saying, "oh, she's a bit tired because end of term and tests", I say welcome to the real world. This is not the last time she is going to feel tired and overwhelmed with work. I can sympathize with the feelings, I am a university student myself. However, being tired has never given me a free pass to treat my mother like a skivvy, because she wouldn't stand for it. Neither should the OP stand for it.