This isn't really a card idea, and wouldn't work for family far away, but I thought it was such a wonderful idea that I wanted to share... My MIL was invited to a "puppy shower" when her neighbor got a new puppy. She was asked to bring old towels, old newspapers, extra dog food, old hoses, etc, that the new "mom" would then deliver to the local humane society. The new "mom" served a light lunch, they played some cute "puppy" games, and everyone enjoyed the new "baby."
She had a terrific time and felt good about donating to the shelter!