In addition to all the great advice, I'll add the following - Yes, you must BOTH be able to solo the boat. With our daughter (starting at 3 mos), we lined the vberth with pillows, closed the door so she couldn't fall out, and opened the foredeck hatch so we could see her and for ventilation. Most of the time, she fell asleep when we left the dock and awoke when we tied up again.
On hot days, we plugged the cockpit drains and filled the cockpit with water, even while sailing....keeps your feet cool too!
The final comment is an observation that at 12 years, our daughter has seen water snakes, heron, egret, rays, dolphin, crab, fed ducks while pierside in the rain, kayaked, swam the Chesapeake in November, can steer straight, seen the water in all its moods, and can cleat a line properly. Growing up on the water is a magical experience for kids and it doesn't have to change as they grow. A suggestion though - let them bring all the friends that they want, else they'll become bored and not want to come. Also, keep the days short and find out where all the swimming pools are within a short day's sail.
Good luck - you won't be sorry.
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