Because having a sense of humor about it helps - Here are some card selections.
Mother, I Know You Missed My Recitals, My Ball Games, and My Graduation, But I Understand...You Were 'Tired.'"
You must be so tired. It’s got to be exhausting always being right.
You taught me the value of money. I’ll be sure to find a “deal” of a nursing home for you.
Happy Mother's Day.....I remembered the card, isn't that enough?
(some language but hilarious!)