if you do go cruising, make sure you're choosing the right cruise line for you family. if you have two adults and like a 5, 10, 15 year old you most likely don't want to take a Royal Carribean, a Carnival or Disney, might be better.
Cruised years ago when girls were little .sometimes for 3 weeks through Suez etc. now a couple,we see plenty 3 generation families cruising and really enjoying it. Recommend it!