I would fish shallow reefs with small bibbed minnow lures.
We have been doing it up here for years and it really is non stop action. I don't have kids but have fished with plenty of them, and they are very much the same as women or blokes who don't fish very often - i.e. they get bored easily, and don't have experience with tackle to be able to be doing things like lots of casting, or popping.
We use small minnow lures like 8cm rapala xraps, with an 8-15lb braid spinning outfit and 20lb leader - barbless hooks of course. Just drift along the edge of the shallow reefs and cast onto the shallows, or around any bommies. If the tide is high enough we go right onto the flats and just cast around the shallows. Make sure they watch their lure the whole time and just use a simple, slow rolling retrieve.
The only accuracy required is to hit the water, and with floating shallow divers that run through the top half of the water depth, you don't have to worry much about snags.
Last weekend we were fishing a shallow reef off the coast, north of here, and were literally catching a fish every couple of minutes. There's nothing better than seeing a little reef bullet come flying out and attack the lure, and you never know what it will be. Cod might drive me nuts but it is a whole different story to someone catching their first fish on a lure.
Plus they will see turtles, clams, sea cucumbers, stupid longtom getting spooked and bolting across the surface, baitfish getting smashed, all sorts of things. This regular action and activity is what will make them fall in love with the sport.
And once they are comfortable with the gear, you can move them onto bigger fish. A few years ago I made the mistake of putting my new girlfriend onto a mack tuna (which I hooked for her) when the biggest thing she had previously caught was a baby bream
I watched in horror as my spin rod was bent into all sorts of crazy shapes and had several near misses with the gunwhale as the fish powerdived under the boat!