Since you will be apart on the anniversary, I recommend that you send flowers. A dozen roses is always nice. And even if your wife doesn't like it, her mother will. It will brighten the kitchen table for a week. And on the card, you can simply say "Happy Anniversary. We can celebrate when we get back home." Or something like that. If you want to give a more personal gift when you get back home, something the boys helped you pick out on your trip would be nice. She may not like you, but she loves the boys, so make things from all of you.
