OP I totally understand where you are coming from (I’m an GP, need I say more?!) and I’m sorry so many people are attacking you about educational policies etc. even on this thread, which is not what you came here to discuss. I do understand that ND kids are very much struggling in mainstream education (I have one myself), and it sounds like you do too and are generally sympathetic to and supportive of and loving towards your SIL. It would be nice to have the same back and a bit of awareness that ranting on about how stupid and uncaring all teachers are etc. to you is hurtful. Though as others have said if she is ND she may genuinely not have stopped to consider that. I definitely think you should spell it out for her. I like @Gardendiary ’s wording.
The teacher-bashing in society seems only second to the GP-bashing to me, especially since the pandemic, so I have a LOT of sympathy for teachers. Social workers get it too to some extent. And we are all under so so much pressure as it is. It’s not easy feeling universally hated by everyone while you break your back for not a whole lot in return, working in a broken system where you are actually only ever trying your best to help people. In fact I see a LOT of teachers and social workers really struggling with depression and burnout due to the pressure of work together with the constant bashing of their roles.
The people commenting that you are too thin-skinned or need to learn resilience likely have absolutely no idea what it’s like to come home from a long stressful day at work and still constantly hear criticism in your face from every angle about how awful/stupid/greedy/lazy/uncaring/useless/cowardly etc you are. Especially in the pandemic. One patient actually screamed at me out of the blue down the phone saying it was ridiculous that I was being paid furlough money to have cocktails in my garden - no idea why she thought that, I was sitting at my desk at work as I did every single day during the pandemic… or as many would say “hiding under my desk” apparently.
There have been so many negative articles in the press and discussions on social media etc. The last straw for me was watching Would I lie to You during the pandemic on a Friday night trying to relax and switch off at a time where I was really struggling with depression due to the stress of it all. I was enjoying it and then Lee Mack (who I normally love and think is hilarious and quick-witted) made some off-the-cuff joke at the expense of GPs, and something in me just broke. I had to switch the TV off and just sat and cried and cried, thinking ok not only can I not read/watch the news (even though I actually have to, to keep up with what the government have said they want me to do at work today), listen to the radio, go on social media, speak to a taxi driver, speak to school mums etc, it seems I can’t even watch a comedy panel show on a Friday night anymore apparently without someone having a go at GPs. It’s just absolutely relentless.
When that’s the background you’re dealing with, as OP says you just need your family to be a soft landing place and not somewhere else you have to have your guard totally up. I had to say to some of my family at one point when they started up with moaning about GPs that it was really really upsetting me and could they please just not. It was particularly irritating as in the next breath they’d be asking me for advice about their health issues. They did think I was overreacting/irrational about it (as I say they have no personal experience of it), and couldn’t understand why I was taking it so personally, but did agree to avoid the whole topic (other than asking me for health advice!). That is definitely going to be trickier for you because teachers and schools are going to come up as part of general family chat, especially with ND kids. But you might have to just agree to generally avoid the topic between the two of you, or only talk to you about that topic if she feels you can help with something with your teaching background and remember that you’re a teacher and you don’t want to be lumped in with “all teachers are…” or seen as a representative of the teaching profession/figurehead. I totally understand that dynamic as well. People do sometimes attack you as if you are solely responsible personally for anything negative that’s ever happened or any criticism that’s been made in your area of work.
People might well say I’m thin-skinned, and to be honest yes I think I am! I’ve always been a sensitive person, and easily upset, a lot of patients do appreciate sensitivity in a GP generally though. It’s not a sin to not be thick-skinned though. I also have bipolar disorder and tend to depression which does affect my resilience.