@Pollylong I completely get everything you are saying.
At our last family wedding, my kid managed to pull me over (I was wearing heels and went down like a sack of potatoes) and an hour later lobbed a pint glass of coke on the floor because he was so dysregulated, and I found it really hard because my family said similar things.
I felt like screaming at them that the way we parent was supported by 2 therapists and a sensory therapist, and if they had the slightest inkling of the things we are dealing with every day they might just realise how much damage (and how ineffective) the naughty step would be.
I can't speak to my mum about parenting my kids any more, we have had to have an agree to disagree conversation, and it just feels like a whole channel of emotional support has been locked off. You aren't alone, but it sucks. I always said I used my parents for emotional support, but she refused to engage with any of the podcasts or reading our social worker recommended, and is determined that fresh air, exercise and straight talking fixes all manner of problems, which isn't actually very helpful.
I don't have much advice, beyond finding some coping strategies that make it more bearable for you. I enjoy leaning into it and making petty revenge as outrageous as possible. My personal favourite thing to do is that, regardless of their behaviour, when we leave we, get McDonald's, pizza, go to a toy shop, whatever, and not hide it at all from my disapproving family who think I'm spoiling them. Fine. Let them be spoiled. I don't have to be a perfect parent. There's no law that say I have to punish my kid when they are dancing on the table, ya know? Letting them be feral and rolling my eyes, saying things like 'god, some parents just hover over their kids, don't they? I'm raising independent kids.' whilst mine climb the curtains and jump off walls really grinds their gears as well. Loudly saying "you know our family rules, don't throw hands if you can't catch hands" also really winds them up because they have this image of their own kids being rough and tough, but get aggrieved when mine enter the fray and take it too far. I also let them have unlimited tablet time at the party and a pocket full of haribo for bribing them or distracting them, and say "hey, it's a party, we get treats at a party!"
If they wanna see 'bad' parenting, fine. I'm the laziest parent at my family parties. I encourage them to go to grandad for a cuddle and they feel cross, to tell uncle Jim how they really feel, to let aunty Millicent dress them. Sometimes I even encourage family members to try and get the kids to stop doing whatever feral nonsense they are doing, succeeding briefly then watching them forget and do it again, then very publicly saying "oh, you know uncle bob has told you not to do that! Why didn't you listen to uncle bob? Uncle bob, can you tell them again?" And then every time it happens refer them to uncle bob, until uncle bob gets the message that its bloody exhausting and probably not worth it. It also protects my relationship with the kids because i can say well it was uncle bobs rules that you can't do xyz, not mine, so now we are home it's ok.
To be fair, this mainly works because my kids are high energy, impulsive, as yet undiagnosed ADHD and I can count on them to be their truest most ridiculous selves in almost any social situation. We have to work very hard to suppress them at the actual important moments (I won't let them ruin a funeral or wedding ceremony, for example).
Sometimes I think people need to experience what it's like and get a taste of it. Fine, let them show you how to do it whilst you sit back with a gin and tonic. Soothe your kid how you would normally, but let someone else run themselves ragged trying to police their behaviour if they want to criticise you.
Knowing you can't win their approval, and radically accepting that has been the only thing that worked for me. People want a sanitised version, where you roll out these well behaved kids and they clap you on the back for adopting children who conform. Being messy in public challenges their view that they could do it and it would be easy. Blaming you is easier than truly acknowledging the challenges our kids face. It's also hard when you might be the only adoptive family in your social circle, so you end up being the token representative of adopted kids too. That weighs heavily on me sometimes, as well as being the only LGBT family. It's all these expectations of ourselves that I'm trying to work through and put to one side, and I'm trying to turn up authentically, warts and all. I don't have to prove anything to anyone. If they didn't want me, I wouldn't be invited. If they invited me and didn't want to then they need to grow up.
Anyway. I hope the wedding has been a nice experience for you in other ways. I always find big family events knackering, but I do love a beige buffet and a cheese and ham quiche, and am always relieved that I don't have to think about what's for dinner, so there are some small perks!