Of course,Richstacy is correct-the best way to avoid children in the dining room is to opt for late seating. But 8 or 8.15 is just too late for us. 7 would be perfect
But there are ways around everything nowdays. I used to believe that we HAD to show for dinner or else our table mates might be offended, or miss our stimulating conversation. We tried alternative dining a couple of times on Princess a few years back and loved the change of routine. Now, the first night at dinner, we announce to our table mates that we won't be at dinnere everynight, that we enjoy a change once in a while, especially if we're late getting back to the ship.
It's your cruise that you worked hard for-you don't have to be annoyed by kids or anyone. There are options!