AIBU to refuse care for my late dad’s wife?

That's fair, but how could you really know what she's like? Maybe building bridges would be beneficial? I imagine she feels the odd one out. Perhaps she's put on a personal and put up walls to cope?

Are you saying we all have an obligation to provide care for people we have liked at some time in our lives? How does that work?

What a charming post. The OP said at times when they couldn’t help their mum they paid for
help. She didn’t say she didn’t help at all.

You can never expect help- i have a sibling and although he is as much Mum's child as i am he moved to the US and completely refused to help.
Expecting you to help with your step mothers care is cheeky of your step sibling- you will have no expectations of any inheritance from her, but your step sibling will- so they are very cheeky indeed, even if she had brought you up (which she didn't) you still can have no expectations from her. Your step sibling just wants to keep the cost down so their inheritance is protected- tell them to get lost.

"practically raised you"....after decimating your family unit. The half sibling won't ever understand that reality. I'd be casually kind, but not feel responsible in the way the half sibling wants.

Could not have said it better.

It sounds like your mind is made up and you've closed that door, then. 🤷‍♀️

Sounds like someone is trying to outsource their job to you! Tell her nice try…

The only reason to do it is to support your sibling. But it sounds like you have closed a door on that relationship.

You have no obligation here. I feel a bit of sympathy for your half sibling because I was alone helping one parent and it’s very overwhelming. But you can absolutely say no with no guilt attached.

"why do you think she raised me? You have no significant memories of when I lived part of the time with your mum. You were a toddler for most of it. She didn't raise me. When I was at your house, my dad raised me, not your mum. It was her choice to stand back from parenting me, and that was her right. But don't go telling me that I owe her because she raised me, because she didn't. She cooked some of my meals, and that was it"

You don't have to become a carer but I wouldn't bring the affair in to it as a justification. OK it wasn't the right thing to do but it was 40 years ago. You wouldn't even remember a time before her. They were together far longer than your parents. Marriages end and it's pointless being bitter 40 years later.

'Virtually a stranger'?

Come on.

OP spent 40% of her time from the age of 6 living with her. She might have not been the warmest of step parents and that doesn't mean OP has to provide her care but they weren't strangers.

MN is so horrible about step mums (yes I do realise this one was shagging the dad but a- he's also responsible for that and b- she lived with OP for most of her childhood and cooked her meals at the very least).

I think that as mums know, unless someone is doing everything, then the other partner is doing something to make things work. So perhaps she did more than it looked.

Aside from that, "care" comes in different forms - money, random visits, delivery of cake / essentials etc, and maybe your step sibling is just looking for some compassion for the person that was in your life for 40years in some way.

I think that is fair enough. You don’t sound cold, it was a complicated situation and you have complicated feelings about it. And that’s all ok.

It’s fine to move on with your life.

As a step mum I think, depending on circumstances, it is unfair to say 'step mum didn't raise us'. I certainly feel like I did with my SC. Shared with their dad I did hair washing when little, baking birthday cakes, tidying bedrooms, taking to extra curricular activities, shortening school trousers, organising holidays, offering emotional support etc etc. I don't know what that is if not raising children and I can't imagine I'm alone. I'm on very friendly, although not really close, terms with them as adults but here's the thing: I absolutely do not expect them to help me in old age. I hope my own DC does a bit, even if it's only to coordinate professional care, but it's never crossed my mind that my SC would carry any responsibility.

Nope.

Not half sisters fault that she is the sole carer, but sure as hell isnt @AnotherPosterUsername and her siblings fault that their father fucked someone else and broke up their family.

They owe half sister nothing.

As for the post about "Do it or you will lose out on the inheritance", be your age! There will be no inheritance to @AnotherPosterUsername and her siblings, care given or not. It will all go to the half sister whatever they do!

You don't sound cold.
You never connected with this woman and that is how you feel.

Hard agree.

SM might well need care for 10 years or more. You’re right to think hard. Half Dsis is facing a hell of a job on her own.

But presumably she’ll inherit the lot so

Personally I would give some kind of bare minimum care because she most likely gave the most care to your father.

How they got to together 40 years is irrelevant, it’s was probably the right decision.

I agree with this - you’re not wrong Op. Live your life & don’t give this a 2nd thought.