Another day in paradise

My job as a teacher wouldn't be half as hard if kids didn't pick up language, manners (or lack of) and habits at home. I have in my Y7 class a little Madam, who can be very cute but also very manipulative. She moved form into my class a couple of months ago, apparently after some problems in French lessons. Let's call her Amy. Amy's very quiet, lacks confidence and is not the brightest of girls, although she does pick up some knowledge in lessons and is not quite bottom of the class. Her quiet, manipulative ways are much more damaging than a kid who explodes with rage in front of you. Let me explain what I mean. At one point, a few weeks ago, she started refusing to come to my lessons, and the first I knew about it was when I was informed of it by my head of department. I had no idea that she felt so bad about it, as she's never said anything and her results, as I said, were not as bad as some other people in the class.
So the school bent over backwards to try and persuade Amy to return to the French lessons. They asked Mrs G, a behaviour manager (quite high up on the food chain and an ex-languages teacher) to sit with Amy in her French lessons for a while, in order to boost her confidence. As if Mrs G had nothing better to do with her time, but that's beyond the point. It seemed to do the trick. Little Madam still asked at the start of each lesson if she could sit in this/that/the other seat, and I gave in more often than I would for a normal kid, trying to boost her self-esteem.
Until today. Students had a list of ten words to learn for homework, and as always, I did a test at the start of the lesson, which students then peer-marked. A lot of kids did quite badly (I think the idea of homework is beyond them), but when I asked students to give me their results out loud, Amy came to show me her test, marked 0/10. I did not comment, and when she asked if she could go outside, seeing that she was nearly in tears, I allowed her, thinking that I would go and speak to her as soon as the class was settled on the next task.
Only when I did, Amy had gone. Which in itself is not allowed, but I thought she'd gone to see Mrs G, and as it was just 5 minutes until break time, did not contact the students managers.
Only, Amy had used those 5 minutes to call mummy, who immediately came into school and asked to speak to me, just as I was about to make myself a coffee (damn!). Mummy, it turned out, was anything but warm and cuddly. The first thing I noticed was her blurry eyes (not good), her chavy outfit (I want one of those!! not) and smoker's face. The language was quite elaborate as well. She started off: "Don't ask Amy to read out her mark in front of the whole class, when you know she has confidence issues, that's why she had to move sets, because the previous French teacher was crap" (more or less). But then when I explained I didn't ask Amy to read out her mark because she'd shown it to me already, she exploded: "And why do you let another kid see her test and mark it?" (hmm, adorable daughter obviously forgot to mention that the other kid was her best friend, and that through whining and begging she managed to be allowed to sit next to her). Is this the point where I should mention peer assessment? Or volunteer lovely mummy to mark all 60 kids' tests that I gave on that day? Probably not, I think to myself. I'd realised mummy wasn't really waiting for an answer anyway, continuing in a linguistic crescendo, to finish with the dramatical, delightfully well formulated statement: "My kid ain't f**ing coming to your f**ing French lesson no more!!"

Gutted!!