The pair of them need telling, very firmly, that you will NOT tolerate their rudeness.
Your DH is pre-Diabetic. He can reverse this if he chooses to, question is, does he choose to?
If he does, either buy the book The Diabetes Code by Jason Fung or read everything on his IDM website or listen to his free podcasts. It’s all there for free, it’s just a bit easier to read the book in some ways.
Diabetes.co.uk (thev ed one - not .org the blue one) is a brilliant site too, the Forum in particular is great
NHS staff are often still ‘recommending’ the healthy plate/food pyramid nonsense, if he follows that he will end up with diabetes. There’s a slow acceptance that low carb is the way forward, but it’s slow to reach the frontline staff and even then the majority of them don’t understand it well enough to be fully on board.
Its not a ‘new’ concept, it goes back decades, it’s how they dealt with diabetes before insulin was a thing, but the misinformation over the years has been diabolical.
Eating Keto & Fasting (even intermittent 16:8) will reverse it if he wants to. Feel free to PM me if you want to talk about any of it.
But he’s an able bodied adult who needs to take responsibility for his own health. Support is great, but you’re not his mammy.
DD is a different matter. You ARE her mammy and as she’s not capable of cooking for herself, relying on carers to prepare her meals I would cook for her. BUT depending on her mental ability to understand you’re POV, I’d either gently remind her that good manners dictate you aren’t rude. Or have serious words about her attitude if she doesn’t have SN.
Sending you strength to cope with it all 🌷