In short, my sister-in-law gave us a check for an amount greater than what I feel she "owed" us, and I don't know how to gracefully give her back some (or all?) of the money.
Long version/background: Some months ago, my husband and I had made some loose plans with his immediate family (mother, father, sister and her husband and child) to visit Town A for a weekend trip to celebrate his mother's birthday. Conditions in Town A were not favorable, so it looked like the plan was going to be cancelled when my parents offered to let us use their vacation home in Town B. This worked out wonderfully for everyone, and I took on the role of hostess (with my husband as Assistant Hostess
Saturday night, we all went out to a restaurant for my MIL's birthday dinner. The agreed-upon plan was that my husband and his sister would split the dinner bill 50/50, which sounds fair in theory, but doesn't end up very fair when my husband and I order a few cocktails while SIL and her husband have iced tea. So when the bill came, we just paid for the whole thing and told her not to worry about it. It was kind of expensive for us, but not that big of a deal, and nothing else was really said about it.
Well, just as we're all leaving to go back home after the weekend, SIL hands my husband a personal check, which he doesn't look at right away. Later, he tells me that the amount of the check was equal to the entire
cost of the dinner and drinks for the whole table, not half.
I'm interpreting this as a token of their appreciation, since we saved them the cost of a hotel and provided the majority of their meals (which was also a bit expensive for us.) But SIL did contribute quite a lot to the weekend. She and her husband brought a substantial amount of food for the house, they drove us around, and she was awesome with helping out with dishes and cleaning. They were really great guests, and apart from the whole restaurant bill thing, I felt they contributed almost as much as we did and I don't feel right accepting any extra money from her.
To put it in perspective, let's say her share of the restaurant bill, realistically, would have been around 50 bucks. The check she wrote was for $150. How do we give her back $100? Or should we just tell her thank you, but we're not going to cash the check at all?
Or is this a gift we should just politely accept, much like a birthday or wedding gift, maybe?
Any thoughts at all are welcome.