Feel free to ignore this, but it sounds like you may take the family on an offshore passage. You might be happier with something that has seaberths where you don't have to worry about the kiddos rolling around so much. Narrow single berths are great for kids, and on passage get the crew home well rested. But they are rare in modern boats, which, frankly, are more at home in a marina than sailing offshore.
It's a bolt out of the blue, and again, feel free to ignore, but look at this:
1975 Nautor Swan Sail Boat For Sale - www.yachtworld.com
These older Swans are tanks, you can have 2 girls in bed in the pilot berths while you play scrabble on the saloon table. The cabin is not so large that you can get pitched across it and injured while at sea, it has a true seagoing galley for preparing meals underway. It will probably come with a bunch of gear, has full safety gear (which I can attest is quite expensive). It apparently sailed in the 2000 Newport-Bermuda, which has one of the most stringent safety inspections. Being a pedigreed boat, will always be worthy of upgrades. And it will sail well.
I have a boat with pilot and quarter berths, and have hundreds of offshore miles with a little kid aboard. The ability to put him in a snug, secure pilot berth with a lee cloth when he was 8 years old offshore was invaluable. Secure single bunks for the off watch are not a luxury, they are a necessity.
If you are going to stay near shore or just daysail and weekend, ignore me.