We are leaving on Truimph March 27 with 19 people....10 adults and 9 kids. Our most experienced cruiser has taken over as our "director" but we have been dealing directly with a cruise agent. All the $$ issues were dealt directly with the agent....don't want $$ coming between friends. We all happen to have kids that have spring break together and our attitude was that if you could go - great, and if not, sorry but maybe next time! We all have agreed that we don't follow anyone's agenda - this is a vacation for each of us and we can do what we want. We have a list of excursions and have chosen some to do...but not everyone will be doing them.
The secret is to be flexible and not to get caught up and worry about everyone else - they are adults (or at least some will be) and can make choices for themselves.
I say go for it. What fun to talk about in the years to come, you'll have lots of "Remember when 's" to share with these special people you have chosen to spend precious vacation time with.