To wonder about the OP whose daughter had ASD and she was going zero tolerance any associated behaviour for the happiness of her other child, herself and husband.

I think the issue about validation of feelings is interesting. I dont agree that all feelings need to be validated but currently that is the general narrative about how to manage all children, not just ND (and adults if you work with adults)

There are times of course when someones feelings are not reliable, in fact feelings are often unreliable. Acknowledging feelings is not the same as validating them

I think its a problem to do that as a blanket policy.

I think we are often between a rock and a hard place in terms of trying to navigate that though.

Of course. But there are commonalities.

Thank you @MargaretThursday and I’m sorry about your childhood experiences with your brother.

I feel terribly guilty about dd1. She has a therapist she goes to (self initiated) and I’m pleased she took this step and can speak to a professional about whatever is on her mind. Our relationship is in a good place now (I’m taking her to Paris this week) and she knows I take full responsibility for the huge mistake I made 2 years ago. I take extra care to check in with her regularly and ask how she is. But she’s hurting like you say and I feel so powerless to stop dd3 being so bloody awful to her 😢

Well NT people don’t have a hope in hell then do they!

There isn't one "autistic communication style" though is there?
I'm autistic and have struggled with other autistic people in the past. Just because I'm autistic doesn't mean I can easily communicate with anyone else diagnosed.
To be honest I don't think there's one "NT" communication style either. Everyone is different.

Autistic children (like nuerotypical children) aren't all the same. What works for one may not work for another. I've an autistic child with adhd and we've kept him busy. Running, volunteering, scouts etc. I worry about the future but try to focus on developing his skills, it just takes more time than his peers. He'll never withdraw to his bedroom. He won't be a high flyer but I'll be so pleased if he is able to keep a job and live a happy life.

I think yes, learning about autistic communication would be extremely helpful, just as autistic people are expected to learn the ways of neurotypical peers. That’s the only way to resolve the double empathy problem really?

Have you also validated dd1's feelings too though?

Because as the one who always had to back off, do more chores, give up what I wanted to do, I would have so appreciated an acknowledgement. The "well I haven't seen you do anything wrong, but you must have to make them react like that" is very hurtful. It feels like really they think you have done something. You may have apologised to her, but I'll bet you did it quietly, so not to upset dd3.

Nothing remotely on that scale, but I remember one holiday. We used to go to a self-catered place and the rule was we all did equal chores. Normally we went for teams, so team me and dad would do the picnic and Mum and brother would wash it up when we got back, then me and mum would do the cooking, and dad and brother do the washing up. Then the next day we'd swap round so over the holidays we did equal amounts. One year, he would have been about 14/15yo. Dbr refused to do anything. So I ended up doing all his as well as mine.
Not one word was said over the holiday about him not doing anything. At the end, my parents came to me and said thank you, and gave me £30 (a lot to me then as I didn't get pocket money) as long as I didn't tell him that they'd given me that money.
I didn't tell them this, but actually I was hurt. Because, you know, if he did something, then he'd be praised to the skies in front of me. It felt like my feelings didn't matter next to his.
I'd have rather they'd said a very basic "thank you for all your hard work this holiday" casually at one of the meals. It wouldn't have had to be a big thing, just that acknowledgement would have meant everything.
And a few months later, something was mentioned about dividing jobs and dbr said that he'd done more than half the work on the holiday, and both parents were falling over themselves to agree with him . Outside they again said to me that I'd done more...
Again it felt like his feelings mattered far more than mine.

It sounded like you validated dd3's feeling enough by expecting dd1 to tiptoe round her.

Please don't feel that I'm having a go. I think you were in a dreadful position, but please don't underestimate how much your dd1 is hurting. She may not say anything (I never said anything even if asked directly) but I'm sure she is scarred by the situation.
And, like my parents, you are too afraid of the consequences to stand up for her publicly.

If it's any help, when my brother went off to uni he got hit by the real world, and that people didn't endlessly make allowances. It wasn't easy for him, but he came out the other side a much better, and happier, person than he went in. He's now quite a decent member of society.

No, I wouldn’t expect that from either party. You’re saying it as though it’s ridiculous, but it’s exactly what is being expected of autistic people. Or is that the point of your comment?

Learning autistic social skills in order to ‘cope’ with being around autistic people… why not, if that’s what’s expected of us?

@WaitingForMojo
I agree

As long as it works both ways, that we’re equally wary of trying to modify the autistic person’s behaviour to an extent where you harm them in order to accommodate others.

In that case, does it mean you expect NT to learn ‘autistic social skills’ and to follow those rules each time they are with autistic people?

Yes, but the environment of the person with ASD also includes other people, and so it's equally important to remember that while you can adapt the physical environment and do the very best you can to alleviate any other pressures you should be very wary, in my opinion, of attempting to adapt other people's behaviour , especially other siblings, to an extent where to help one you are essentially damaging the other.
This is an extremely difficult balance and one which many families have to juggle on a daily basis.
It's a discussion though that we shouldn't shy away from having.

I was told by an amazing Psychiatrist at CAMHS that with ASD, you wont change the child but you can manage the “environment” to pre-empt and prevent the meltdowns.
This advice has worked wonders for me over the years.

There’s a huge difference between assisting an autistic child to adapt to a neurotypical world and forcing a child to mask 24/7. Autistic people are already statistically more likely to commit suicide — as a parent, I’m not sure I could forgive myself if contributed to that risk.

No, I don’t think all feelings are worthy of validation. You can acknowledge that someone feels a certain way, but those feelings can also be an overreaction/inappropriate response to an event.

Well everyone needs their feelings validated don’t they? I liken it to my marriage, sometimes I might upset dh unintentionally or vice versa. It doesn’t necessarily mean we’ve done anything ‘wrong’ to acknowledge and validate the other person’s feelings.

Why do dd3's feelings need validation? And why is at the expense of dd1?

I have two adult children at different points on the autistic spectrum. The oldest, my son, went to a special school. One of the best things I ever learned about helping my child with autism was “it’s the rule.” This makes things universal, that we all have to do, whether we like it or not. Autistic behaviour has to be modified, as does all children’s behaviour, but some autistic behaviour needs specific intervention. My son will never be able to do paid work, but works in a charity shop and in a supported enterprise. He lives on his own in a flat and has a very full social life. If we had not helped him - and it was very hard work - he would not be as independent and well liked as he is.

I suppose so. But dd1 isn't perfect (is anyone?) and there may have been some times when dd1 upset dd3 (not on purpose). I am trying to validate dd3's feelings.

@bendmeoverbackwards but has dd1 actually done anything wrong? By encouraging dd3 to forgive, are you not agreeing dd1 has wronged dd3?

Thank you @Love51 Unfortunately after a year of peace, it has happened again. This time we totally have dd1's back and are trying to support her as much as possible. She now hates being at home which breaks my heart. I have tried to encourage dd3 to forgive (whatever dd1 has done) but she seems stuck. Just wants someone else to blame for her unhappiness I guess 🙁

@FloofyBird So haven't you ever heard of 'trainer' as a profession that is related to humans? At work we have various 'training programmes'. Are we dogs? Our kids get trained, we get trained. There is nothing wrong with 'training'. It provides a framework to help achieve certain objectives. You train for a marathon, so you can achieve the objective of finishing a marathon. You train in public speaking, so you can deliver a speech others find useful and comprehensive. And if the objective is to help autistic kids navigate the neurotypical world easier, it's good. There is already 'training' to society to understand better neurodiversity so they can understand us, neurodiverse people, better. Hope this helps.