I don't really have an answer for you, but I can tell you that at SeaWorld, the Dolphin pool has a waist high wall that reach over to feed and touch them vs. Discovery Cove and other Dolphin encounters where you are in the water with them. This pool can get very crowded at feeding time, and you may or may not actually manage to touch one. At Discovery Cove, groups of around 10-12 people have half hour "appointments" with a Dolphin and trainer (and a photographer), but since your youngest can't fully participate, it might be better to wait a couple of years, since with the price of admission, it's not something that most people do very often.