I have three kids, girls age 15 and 12, and a son who is 8. I started sailing in 2003 and have been at it ever since.
My oldest hates the boat and wants nothing to do with it. She can be a good sport about it though. For example if we are going to spend a few days on the boat I will usually bring the boat most of the way there by myself and have my family join me for the last bit of the trip. My daughter doesn't want me to have to do the trip alone so she volunteered to go with me and help.
My younger daughter doesn't mind sailing. She loves swimming and the beach so if the boat allows her to do those things then she likes the boat. If we're just going to sail for a few hours she would rather not go.
My son likes sailing, I guess about as much as any 8 year old would. He likes to steer and I'll let him do that as long it's safe and he can handle it. I'm working on getting him to trim the sails but that make take a little longer.
My two younger ones like spending nights aboard so that it nice. Sometimes we'll just spend an evening on the boat at the mooring.
When we're out sailing i will ask the kids (and my wife) to name certain parts of the boat. They have the basics down (mast, boom, headsail, mainsail, main sheet, jib
sheets, bow, stern, port starboard, etc.) and I will start on the more complicated stuff.