By Patience, the parent helper. Like many mother-helpers, I am at heart a terrible prig. At primary school I was always good, except for the times I was so hopelessly vague that I just forgot where I was and did things such as walking into walls and wandering off into the playground instead of into lunch. So in the classroom, I tend to be on the side of the angels and to prim my mouth disapprovingly when anyone is acting up.
Mrs Jenkins, the new teacher, is very firm and the Year 2 children tend to speak of her in hushed tones. "She wants all the pencils back in their places every day," said Jake incredulously. I gave a guilty start, thinking of all the pencils in our house which are not back in their places at the end of each day, or, indeed, of each week.
But where a carefree sort would have shrugged this off, I took it to heart and now keep trying to restore the errant pencils to their place. If only I could decide where that was.
So, at the Harvest Festival, I expected to find myself on the side of the angels, reprovingly shushing all those proud parents who leap to their feet with video cameras at the sight of their little angels and giving firm glances to any of our class who showed signs of getting out of hand. Instead, I got the giggles. I could see the effort the staff and the head had put into making a well-crafted, thoughtful and beautiful occasion. But I kept catching Jake's eye.
He was clearly enjoying himself, singing the songs with all his might and, with equal gusto, shoving back the naughtiest boy in the class who was shoving him. Most noticeably, when the head asked us to close our eyes for a moment's thought about all the other people who bring us our food, he caught me out. I kept my eyes open in order to see if his eyes were open. But his eyes flew open just in order to catch me with my eyes open. And when, to his glee, he caught me out, he shook his hand reprovingly at me with an expression of moral superiority. Then he closed his eyes firmly but only for the briefest minute, snapping them open again to catch me, still of course, gazing at him. So badly did I want to giggle that I had to sneeze. Oh dear. I could just remember what it felt like to be six and singing in your school concert - a kind of a mixture of boring and exciting, like a liquorice and sherbet dip.
But now I had another role to play. I am not six any more. I am a mum-helper. So the next thing I noticed was Millie, regarding me with somewhat shocked fascination. Millie is just as good a girl as I ever was and she seemed to think I was letting the side down. I pulled myself together and duly bent my head in reflection. Sneaking a glance I saw that Millie had closed her eyes tightly but Jake still kept trying to catch his mum out. This must be why teachers don't like having their own children in the class. It's all right for a lowly helper to be silly, but Mrs Jenkins, is never silly. She remains in control.
How does she do it? I often wonder this. After spending my one afternoon a week educationally playing with the children, I have just the same feeling which a long day's work followed by a swift gin and tonic gives me - a mixture of boredom and hectic excitement.
The feeling is rather like a six-year-old at a concert and a good antidote to a natural prig.