She couldn't foot the bill.
I think she'd pay for herself, but I'm not entirely sure how she thinks it'll work. It'll also be a lot more expensive once we get there than she realizes and we'd end up paying most dinners/excursions because she'll expect small town wisconsin prices in Hawaii restaurants.
I do not love my MIL very much.
I have told Mrs Pnk if she wants to be a good daughter, she can take her mom and we'd pay for hotel room, but she'd need to pay for her flight and some day to day stuff, and there is no way in hell I'd go