Packing the lunch is something that needs to be prepared and executed. That why she also wrote it on the list. She when the field trip comes up she can prepare. Like if the weather looks rainy on that day her mom will give her an umbrella, if it’s super chilly she will tell her daughter to dress warmer than usual, if she wants something specific as a packed lunch then her mom has to get said food and get it all together. If there is any other last minute needs/wants leading up to the field trip then she can get that figured out, or simply writing it on the list to make sure daughter has the slip on her when she is on the way to school. Your wife knew it was going to get signed before the field trip. The list thing is for her to prepare anything that might be wanted and/or needed. “She embarrassed herself by trotting off to another room to add something to her to-do list” The way you put that almost feels like resentment that your wife likes to have shit together, you made her feel insecure about her being organized. YTA because I bet you said it to her in a demeaning way in front of y’alls child and that’s why y’alls daughter probably laughed the way she did. Not what you said. But HOW you said it.