DD has just started P1. She is an irritatingly very precocious child with a very strong sense of right and wrong. And if someone does wrong she finds it very important to tell the teacher. The teacher has told me how she seems to be very sensitive
and complains about every imagined slight

I have spoken to DD but it is quite hard to convey that yes she should tell teacher about really bad things (another kid spitting in her face) but she shouldnt bother him with minor things (being accidentally barged in the cloakroom). She feels (correctly I guess) that if someone accidentally barges her they should say sorry, but if they don't (most of the time) she then tries to get the teacher to tell them to say sorry.
Any advice on books etc I can use to teach her to negotiate this stuff on her own without involving and adult at least some of the time?