I am fortunate that both my mum (aged 78) and mother-in-law (aged 82) are in relative good health, live within a 30 minute drive and we all have a good relationship.
My b-in-law lives abroad and my brother & his wife, although lives close, can be a bit flaky about socialising with everyone, often changing plans or cancelling last minute.
Every occasion throughout the year Birthdays, Christmas, etc is left to DH and I to organise and usually host. F-in-law only drives to local shops now so we have to collect and take back when they are invited out.
DH is a good cook and does the majority of cooking as a norm, and when we are hosting more I obviously help.
With Mothers Day coming up, unusually we've not yet invited anyone round. For many years I've felt that others forget it's my Mother's Day too (1 DD away at Uni, 1DD possibly working that weekend) and as our weekends are precious, particularly at the moment as we both have important stressful work projects to be completed by the late Spring, I just don't feel enthusiastic about hosting for what will essentially be about 6 hours when I could be chilling and doing my own thing. We can't invite everyone out to a pub or ir restaurant as inlaws expect an invite out means we pay for everyone, and my Mum's partner has a terminal illness meaning eating out is not an option.
Am I being unreasonable to just give a card & flowers and say we're just chilling this year? I know the parents will say that's fine but will probably be disappointed. An alternative is for me to take my Mum out for lunch at some point and he do similar with his (she barely leaves the house though, only to come to us so would likely refuse). I know not everyone celebrates Mother's Day, but those that do, what do you do?