I told my family that I refuse to make more than two meals at our weekly family dinner...AIBU?

You're the only one with enough space, so it has to be at your house - fair enough.
It requires one or two adults to organise, prepare and cook the meal - are you the only adult in the whole family group?

The rest of the family have a cheek expecting OP to pay for their weekly dinner. Time to stop

A autistic child with sensory issues over certain foods is just that. It does not mean they are automatically heading towards an ARFID diagnosis. 🤦🏻‍♀️🤦🏻‍♀️🤦🏻‍♀️

Most children, including those with an autism diagnosis, have some issues over some foods.

YANBU @waterbottle1988 Glad to see that you've taken control of the situation and made it manageable for you in your home.

Your family can bring their own food for their specific needs. If I were part of your family, and I was used to this regular gathering, I'd be happy that you were happy to offer your home on a weekly basis and would do what I could to support you in that rather than expect you to keep giving and giving and giving.

You are hosting just because your house has the most space, not because you have the time to do all that prep. I'd suggest changing the format to being a pot-luck buffet where everyone brings a dish. If you want, you can coordinate it so that there's a range of things on offer, but asking you and your DH to not only host but prepare all those different meals is outrageous. I'd be embarrassed to be expecting you to do that for me.

Or she can get some of the other family members to do the cooking at her house.

Your mum doesn't like it she can go back to doing all the cooking

Come on! They can have the vegan mice 😂

YA totally NBU. I'd also cut it back to once a fortnight, or ideally, once a month. It's ridiculous that you have to do this.

Your mum hadn't 2 young kids when she was cooking for her kids and grandkids.
Anyway, how do your siblings think it's ok to sit into a free dinner every Sunday.
Also, you need to start taking day trips on a Sunday with your own family.
How does your dh feel spending Sundays catering for your family.
I wouldn't like if my inlaws arrived every Sunday for dinner.
It was different for your mum, they are her adult kids and grandkids.
That's a different relationship

a bowl of MICE? This is why no one is eating at yours....

You are not your mum, and are under no obligation to do things the same way she did. Life moves on. You have said what you're willing to do on a weekly basis. If people don't like it, then there won't be a full family lunch every week. And that's fine too.

YANBU

You should have started the new tradition of a potluck. Or cut back the family dinners to once a month.

you don't consider your siblings your family? I find that really sad.
my sister is my family, are are my siblings and my extension so is BIL. My MIL is my family because she'sy husbands Mom and my children's Nan.

id be really hurt is DSIS referred to me as my Mom's family not hers

@waterbottle1988 how many do you host for?

How about a monthly dinner where everyone chips in for a decent takeaway?

I don't think YABU to make one meal, but I would try to make that meal more easily customisable.

Shepherd's Pie is difficult because it's all so smooshed together, whereas if you made a Bolognese , for example, you can keep everything separate and they can serve themselves. It's easy to do a bowl of mice, bowl of vegan alternative, bowl of plain spaghetti, bowl of cheese, two different veg, salad and garlic bread. Then everyone can find something to eat.

Hosting on a weekly basis, you simply shouldn't be held to the stringent standards your mother apparently expects. It's fine if that's the way she did things, but you're not the same people and you are not under any obligation to make the same choices. I don't think it's rude to tell people in advance what the menu is and allow them to choose whether or not they want to eat what you're serving, bring their own food, or decide not to come at all. Your mother disagrees. Oh well! I'd be very annoyed with her for daring to tell you that you were rude when you're going to the trouble of hosting everyone once a week. Simply providing a place for everyone to gather takes a certain amount of effort on your part, never mind the food!

YANBU.

Also, there's no reason people can't take turns preparing the food in your house if you don't have a problem with it. They may not have room to host in their own home, but they could certainly still bring finished dishes or ingredients to prepare in your kitchen.

Well as someone with allergies in the family YANBU!
We’d always ask what was being made and bring substitutes if necessary to not inconvenience the host.

Bloody hell, rotate!!

Is there a particular reason why it has to be every Sunday? Your parents started the tradition 10 years ago because it was what they wanted to do, and they didn't have young children. Perhaps it's time to reevaluate the expectation and reduce it to every other week, or once a month.
There must be times you'd rather be doing things with just your children on a Sunday, without having to navigate the pre-set demands of other family members.

If you want it to remain as weekly then;

your mum goes back to doing it as she was before (you all fit previously, it can happen again even if it's more crowded than at yours),

You alternate eating at yours, ordering take out or eating out,

As people contribute to the food it's a bit tricky to say you're not longer catering for their preferences, so everyone uses that money to buy/bring something they'll eat and have a buffet.

You strip it back to tea & cake,

Could you do a bbq in the summer months?

Personally, if your mum's not willing to take back control then I think it's time to tweak the tradition and adapt it to what works better for you & your family.

I've been guilt tripped into having Christmas the way my mum wants it, all my life. The resentment is now ingrained & I dread it each year. Don't be me (although I have started setting new boundaries over the past few years)! Don't sacrifice what you & your family want in order to appease other people's demands/expectations.

You are being more than reasonable. Two versions of a meal is enough. Fusspots and those with particular needs can bring their own.

When we host extended family we usually have 10 - 12 different sets of dietary restrictions to deal with, so we’ve got pretty good at cooking the kind of meals that have lots of different component parts that all go together, so hopefully everybody gets stuff they like and it feels like we’re all eating the same meal.

So if you want to occasionally make the different meals for everybody (eg for Christmas/easter) then you could try that approach

eg for our last big family meal we went Italian - chicken Milanese, aubergine parmigiana, pasta that could be plain or with bolognese or with roasted veg or with cut up sausages, garlic bread, caprese salad, a white bean and courgette salad, plain green veg, focaccia. A lot of it could be made in advance or bought. Everybody got at least one protein, one carb and one veg that I thought they’d eat and everything went together.

We’ve also done Turkish, Mexican, American, etc.

Just throwing it out there.

How often do you see your in-laws? What happens if one of your DC has a sports club on a Sunday?

It's ridiculous to do all that once a week. I'd switch to doing it once a month. It must completely dominate the weekend.