I'm traveling to St. Thomas with my niece, her 5 year old son, and 3 year old daughter. I've been to the The Baths and would like to share the experience. How will the 3 year old fare? I'm afraid it will be too long of a day for her and she may end up making the rest of us miserable. Also I'm finding the trip to be $250 per adult $160 per child. Anything less expensive?