Most families coordinating care for an older parent end up with one of two problems. Either the main family WhatsApp bloats with logistics, rotas, GP appointments, who's doing the shopping, until nobody can find the photo of the grandchildren anymore. Or a side-thread starts up "just the kids" that quietly excludes a partner or the carer who would actually have been useful in it.
The Family room is the small calm place in the middle. It lives next to the daily check-in and the shared visit calendar, not next to the holiday-photo thread. Everyone in the Circle is in it: the siblings, partners, the carer if they've been invited. Nobody who shouldn't be there is in it, most importantly, the person being looked after.
It's the same conversation you were already having. Just in a place where you can find it again next Tuesday.