I always find that keeping it short and the action fast, is the best way to get them hooked (if it is something they will like)... When my boys were a little older and I took them to the salt and put them on an Epic Blue Fish Blitz, my younger boy got a couple and said "that was fun", put down the rod and took a nap... My old boy could not get enough! I will let you guess which one is now a fishing guide and which one is an electrition...
As much as my granddaughter wanted to handle and release the sunfish, I just let her touch them and see the spines... Next time if she gets stabbed or hooked, she will be better ready for it. The best part is she wants a Next Time!