While you're being told it's none of your business, YOU are the person they all want to conscript into serving as a nurse for this very needy granma. That's way too much for them to assume you'll do. I've been a caregiver to elders, both professionally and within my family. It involves a LOT. No one has the right to just stick you with this job that you didn't volunteer for.

Your dilemma is that you don't want to disappoint your husband, especially if he was helpful with your mother. That puts you in a quandary. It's still not a reasonable request. You and your husband should go alone and get a room to stay overnight in.

An alternative might be for your husband and his brother to split the cost of hiring a nurse's aid for the trip. Maybe your mother-in-law has plenty of money and could pay for that herself. Even that's not much of a solution, since you would still be stuck supervising that her needs were being met.

It does sound like your husband lets the family sucker him into bad deals. Maybe it would help him, if you just put your foot down and said "no."