I know more about being the parent of a teenager than I do about being a Liveaboard, of which I am both.
Make sure each of your kids has his or her own space to call and care for as their own or they're going to go nuts -- and drive you nuts, too. (I'm probably not telling you anything you don't already know.)
I am a new Liveaboard, a mid-40's single male on a 29 foot sloop in Newport, Oregon, altogether different from your situation. My boat is big enough for me alone, although I wish I would have gone a few feet longer and wider. I am learning as I go: the first lesson I learned was about space management and purging possessions. Be ready for that.
Other than that, I am going to back off and let the more experienced Liveaboards respond to your question -- and, if you don't mind, learn from their advice myself as well.