I think it is nice and right if DH's give you a card, you are still a mother even when your children are too young to make you a card themselves. Your DH, and your other relies, can appreciate you as a mother too. I think it is nice.
There is a real divide on here when it comes to MN, you get the ones who 'don't care, it's just a day, every day is about being a mother', the ones who expect an awful lot, and the ones who expect something nice but get nothing as their DH's are selfish twunts.
I think there is no harm in expecting a nice relaxing day, and a card and a cuppa in bed at the very least. I got all of that, a crochet book which was more than I was expecting, and DH has taken DD to his mum's for the day to give me a break, which was my only request. Maybe that is not what being a mother is about, but I am a mother every minute of every day, and I need a break.
As long you treat your DH the same on father's day then it is all fair. I am lucky that DH and I have similar views on this, plus we actually have conversations about each others expectations, so one of us isn't sitting their fuming while the other is oblivious.
Sorry, that wasn't really an answer to the OP, more the myriad on Mother's Day threads.
OP, you are not odd, but neither are the people who expect just a little effort from their DH's on a day that is meant to be about them. You are still a mother when your DCs are young and still deserve a treat (of whatever magnitude).