Honestly, let your family decide. Use this as a lesson on economics since it's like found money. Give them some options, let them know what each thing costs. Your 3 and 5 year old may not understand the concept well, but it's never too early to start teaching them to spend wisely. Not that you can't have fun with it. But letting a 3 (or 5 or 9) year old just blow $100 on souvies just seems wrong to me. The souvies are not going to last long, but the memories of a cruise (spending time together) or a photo shoot is more meaningful. JMO