My Mom has dementia and we recently moved her into an Assisted Living facility. My Sister lives in the same town as my Mother. She, my Sister, is now demanding I visit her, from out-of-state (2 1/2 hours each way), twice a month. Ideally I would love to oblige. However, I have three kids, all who play various sports and two dogs. I am married and my Husband is happy to help when he can. I am afraid to commit/promise to coming twice a month when it may not always be possible. I know this is going to make her EXPLODE! She is a very strong/narcissist personality. Its her way or the highway. We have had a very tumultuous relationship with years of estrangement. I would like to avoid a fight but am feeling it may be unavoidable when I inevitably disappoint her.
You're your own person. Analyze your relationship with your sister and why you feel you even need to consider her requests (?) or demands.
It's not the fact that you have a husband and children or have other commitments. Again, it's the relationship with your sister that's the issue.
There are a lot of posts here on setting boundaries with parents; they could apply to relationships with siblings.
My sister, who I don't think is demanding, would have a fit if I stopped helping my mother on at least a weekly basis. But our mother is not in assisted living, and we share many responsibilities such as shopping, medical appointments, and household tasks for my mother.