Yes she should have acknowledged the card, and yes she could have wished you a Happy Mother’s Day. But no, I don’t think she needed to get you a card. You say you get her a card every year, why is that? Because she’s like a mother figure? Because she is in fact your partners mother? Do you (and her) buy a card for every single person that is a mother in your family on Mother’s Day? If yes, then sure be annoyed you didn’t get one. But if no, then don’t be.
See, you're being a little rude now. You asked for people's opinions on her not getting you anything for mothers Day, and you got that. You didn't ask for people's opinions on her, not saying thank you for said card, and obviously, no one has commented on that. Although I'm sure she said thank you to someone, maybe not directly to you, but I'm sure it was there somewhere. Furthermore, just because your family does, it doesn't mean your partners the side of the family does. I'm assuming she's never got you a card in previous years, and it's never been a problem. Maybe she doesn't know you suddenly expected one. Again, she's your mother in law and you're her daughter in law the clue is in the titles. For most families, you wouldn't get one except off your child/partner.
Incognito yes I come on this app when I have time on my hands. We all do
I see it like this; I don’t need anyone’s validation let alone a MILs. Also when I choose to make the effort there is no expectation in receiving anything in return otherwise again I’m doing it for validation or due to some insecurity I have within me.
She should have said thank you for the card, but I don't think she's rude for not getting you a card. You said that giving cards is a thing on your side of the family, but that doesn't mean it has to be the same for your MILs side of the family. It sounds like you do care about this and if it is a big deal to you why don't you bring it up with her?