My mother has Alzheimer’s and we are preparing to get her into assisted living. My brother's wife and my sister's husband feel it is disrespectful to not include them in all discussions and decisions as it regards my mother. I feel it is too tender-hearted a topic for so many people to be involved in. The relationships are difficult at best. Must they be included?
My brother-in-law treats my mom like sh*t and I don't feel any responsibility to include him in anything. My sister is always forwarding stuff to him about my mom but I don't think he has ever responded directly to any of it and he so obviously doesn't care about her.
When my mother needed to go to a nursing facility for rehab, my two brothers and I worked together to choose a facility and do everything to get things ready for her to go back home. My husband and one sister-in-law weren't extensively involved but they were welcome to be if they wished. My other sister-in-law was invaluable to us in the advice she provided because she'd been through it before with her own mother. She helped us vet the facilities we were considering but due to Covid restrictions, just my brother and I did the site visit. My situation may be a little different than others, we all consider ourselves family and we all have a voice. I am so grateful to have their help especially when I think of my husband's situation as the only surviving child.
You should also consider that the spouses who aren't given any consideration in the decision-making are more likely to criticize the decisions made, particularly if their spouse (your sibling) is passive about decisions and pitching in to help. You are understandably upset right now, but many difficult decisions are ahead of you and it is time to be more practical and less emotional about your mother. Best wishes to you.
I don't think you need to discuss health issues, but I think discussing what would be the best situation for everyone is something that should be agreed.