How can I change my thoughts about my mother-in-law’s comments every time I come with food.

C: I buy groceries for kids
T: why does my mother in-law think the groceries are for her
F: angry frustrated
A: withdrawal, be rude and answer her by saying It’s for someone else, because if I don’t she’ll open the grapes and eat them
R: Be rude to my mother-in-law every time I come home with groceries.

I am trying to be neutral with this model.
Facts, she didn’t ask me to by grapes for her.
My husband and I ask, she says she don’t need anything.
I think it’s her responsibility as an adult to buy or make a list of what she wants and hand that to her son, my husband to buy for her.
Just as it’s my responsibility to buy and make list for me and my kids.
I know I’m playing the victim here, help me to think neutral here.