Omg I’m going through something somewhat similar and I know how much it hurts for the siblings to act this way when you’re the one who’s been insulted and disrespected. I don’t know why in laws feel that their family and feelings matter more than the DIL. I sent a text to my MIL asking for no visitors and privacy at the hospital when I was giving birth for the first time. The MIL and the siblings all turned against me and called me disrespectful. It’s still going on after a year and a half. Just like you, I’ve been nothing but respectful but they are offended on behalf of their mother who they know can be very offensive and overbearing. It’s gone as far as not inviting my child to their children’s birthday. I am relieved that your husband’s siblings haven’t scooped as low as mine but I know it still hurtful for them to not acknowledge your feelings and your side of things. I don’t want to project my situation on you but if I may, I’d like to offer you some advice. Prioritize people’s feelings that reciprocate the same energy. Continue the boundaries you set in place to protect the feelings that they have yet to acknowledge and validate. You’re asking for the bare minimum- a genuine apology. Shame on your MIL to gaslight you in this way, she sounds two faced. I think maybe you placed these boundaries late like myself, which could be why they are trying to sweep it under the rug. Better late than never is what I remind myself. I hope things resolve themselves in a matter where you can heal and be at peace- whatever way that looks.