Should both sets of parents be treated the same on Mothers Day?

He does have a point though. You are putting it all on him, and you do have other children. They should ALL be doing more, whether they have children or not. And it does sound like he did an awful lot for you when he was at home. So it’s a tough one. I can understand why you’d feel upset when you see them all out for meals with her family, but you probably need to say to all your children that it would be nice to see them once in a while on Mother’s Day.

so none of your other children saw you at Christmas either

just how many other children do you have ?

I did everything for him when he lived here

Bollox you did. You said he drove you “everywhere” and that was just for starters

"would always get me similar for Mothers Day"

So continue to expect similar.
It is daft to think he should now start getting you different things?
Just because others do things differently does not mean your ds now has to do the same as them.

YABVVVU
You do mothers day for your mother. She is doing it as she has always done it and so is he. If you've a problem with the amount of effort he puts in then you address the complaint to him. You do not mention her. How your son treats you is about you and him not her.

I was thinking about asking DS to be mindful of treating us both the same this Mother’s Day. I do see how this will come across now so I will refrain.

it is jaw dropping that you were going to do this

absolutely jaw dropping

Are you being entirely honest with yourself about your relationship with your DS? Because you’d always both say you were doing everything for him when he lived at home until recently but also are so disabled you can’t get a train without help? And your other children seem quite keen to distance themselves from you.

Theres still time to repair your relationship with your DS and build one with your DIL but you can’t do that if you aren’t being honest with yourself.

It's dependent on the person giving as to the level. If it wasn't for me MIL wouldn't get anything. As it is level of effort is similar for both, however value is different.
I get my mum a card and chocolates
I get MIL a card and a bunch of flowers or jelly sweets

My mum hates flowers and MIL prefers sweets to chocolate. Sometimes I let ds choose what we're getting them and they end up with the most random things, a few years back MIL got massive fluffy socks while my mum got a rainbow mug because MIL "always has cold feet when she comes over" and mum "drinks loads of tea" and he liked rainbows at the time

before I say something.

Say something???!!!

Not just driving
other caring duties?

what happens at Christmas?

How often do your other children visit you?

Was your son essentially your carer when he lived with you?

Simply put, no they should not be treated the same just because their children are in a relationship together. Everyone has different relationships with their parents. As long as the relationship stays as it was and not change, unless naturally for the better, then you should not expect to be suddenly treated the way your future DIL treats her parents. If you naturally want an improved and better your relationship with your DS then you need to work on that with him because it’s something you want to improve, not because your now jealous your future DIL has what you feel is a better relationship with her mother.

I know no one in the situation

but my hunch is… I’m not least bit surprised this DIL isn’t too keen on the OP.

It sounds like you don't treat him equally. You imply here that he wouldn't ask you out for lunch but you wouldn't want to go out just the two of you anyway because you are not well. However if your other children come then you 'push yourself' therefore make the effort for them.

Are you actually housebound? It is unclear to what extent you leave the home e.g. able to do shopping, or if you are registered disabled and have carers?

Sad though it is to say OP, you are the mother of a SON. There is an old saying:

'A daughter's a daughter all of her life, a son is a son until he get's him a wife'.

Effectively, your son now has a wife (albeit they're not married yet), and his priority is now his wife (to be). Very few brides that I've known have included their future MIL in shopping for their wedding dress, as they don't really know the MIL that well, and don't want to risk her telling her son what the dress is like in her excitement. Then, just to top it off the hurt, when they have a family, you'll likely hardly get a look in with their babies, as her Mum will be top of the list when it comes to babysitting, etc. I'm afraid it just seems to be a sad fact that mothers of sons, don't very often get a look in, once their son gets a partner or wife.

Hence, if you really want a look in with your son in the future, I'm afraid you're going to have to make friends with his fiancee, and as you already feel she doesn't like you, I think you're going to find that a tough job. I'm so sorry that this is the case, but think you need to know that this tends to be the way of things.

Sorry OP but you sound really, really draining.

Just because your other DC have their own DC, you no longer cease to be their Mother. I have DC but we will visit my DM on Mothers Day- one of my DC will come with me. DH is going to see his DM, and he and his DSis are taking her out for brunch.
It will be quite a few miles on the day, both Mothers are a couple of hours away, but I will be back home in the evening so my DC are assembling to make me a curry.
I totally agree with your youngest DS that it is unfair to expect any Mothers Day input should only come from him. He needs to call your other DC and point out you will be alone.

Sorry you are feeling rejected or pushed aside.
I think a bit of therapy could help you as you being jealous of what your DIL does with her mother feels like a nursery type of upset to me.
Your son is right that you also have other children and it shouldnt all be for him to do. Is he the youngest?