It is extremely unlikely that you will find a ride with your entire family. Think about it: you will encumber the boat with three bods, one of which requires nearly constant watching and care. This leaves but one to be of help crewing
. Further, (here I can only speak for myself) a skipper
who would take on the responsibility for the safety
of a small child who is not his own is braver than I am. I love kids
, sailed with mine when they were small, but would not willingly take on someone else's as "crew". The ramifications of injury to a child on board are too severe in today's world.
I'm sure that you and your family are good folks, but seen as a crew you would be a liability as newcomers and not much better if you adults were good hands. BTW, all the above is predicated on the interpretation of your post as wanting to go on a significant cruise
or voyage. If all you are interested in is daysailing, then the prospects are far better. If you follow the advice of many others to join a sailing club or even just hang around marinas
a lot you are likely to fine a sympathetic owner who needs crew for short sails
... and there is your entry point.
Good luck with it all, for it is a great life.