I think anyone who has a destination wedding understands that people will not be able to come. (I am having a disney wedding and I understand that some of my family members won't come) My thought on this is that the SIL doesn't EXPECT you to come, pay alot of $$ give a gift, etc. She's undoubtedly aware that you have kids and it'll cost a lot. I think that the mother is not using her head.
For example. My sister also had a disney weddding. One of my uncle's couldn't come. (He has 4 kids and his wife doesn't work) My mother FLIPPED out at him. She sent back his Christmas card. Did she overreact? Yes. But she felt that everyone should attend her daughters wedding. (I have told her that under no circumstances is she to pull a stunt like that for my wedding)
If you can't go, don't. Make sure that you call the day of the wedding and send good vibes and remind them that you are thinking of them. Send a card, send a gift ask for pictures. The end.
For example. My sister also had a disney weddding. One of my uncle's couldn't come. (He has 4 kids and his wife doesn't work) My mother FLIPPED out at him. She sent back his Christmas card. Did she overreact? Yes. But she felt that everyone should attend her daughters wedding. (I have told her that under no circumstances is she to pull a stunt like that for my wedding)
If you can't go, don't. Make sure that you call the day of the wedding and send good vibes and remind them that you are thinking of them. Send a card, send a gift ask for pictures. The end.