Cavoli why does the OP have to visit her MIL and take her for lunch on Mothers Day? Why does the OP have to arrange it? Surely that is down to her DH to do or not do!
My MIL used to expect that - she was overall a lovely woman but her expectation around mothers day involved everyone dancing attendance on her and driving the grandchildren there. The fact I am also a mother and might not want to spend my day that way (getting the kids up early, clean and nicely dressed and breakfasted and packed into the car with flowers to give her, and then driving to the in-laws, hanging about there before driving to a restaurant, then driving back to the in-laws to hang about more ...spending ten hours with the in-laws before driving the kids home and doing bedtime ready for school in the morning) was never to be mentioned.
In the end I got cross (with DH not directly with MIL) and pointed out the blindingly obvious - that if mother's day was being "observed" as a day to appreciate mothers, and what I wanted was a lie in, not presents or a long day of driving about and small talk and wrangling the kids at a restaurant etc) then why was that less important than his mother wanting us to do all that stuff. Her wishes for the day totally overruled mine in every single way.
In the end he took the kids to her and I stayed at home and had the day to myself, although the kids from about 5 or so started bringing me "breakfast in bed" which they enjoyed and was sweet at 5am-
My mother is just the same as MIL was - when she was a young mother she never visited her mother or sent her flowers on mothers day, just phoned, and she had high expectations of presents and cards and would in fact cry if these didn't meet her expectations. As a mother of adults and grandmother she continued to expect mothers day to be about her, and expected her daughters not to mention the fact they were mothers too, but to behave as if she was also solely responsible for the existence of her grandchildren, and buy her presents, cook her meals etc.
It is an odd phenomenon and I don't know whether its that the generation both our mothers belong/ed to was the one which first really bought into the commercial mothers day in a big way and so felt it belonged to them, or just personalities...