We did it!!
Last April.. we received the ultimate package (there are higher packages) for doing timeshare tour. We were 6 adults between ages of 55-61. I booked it as our gift. Not sure how happy everyone was with me, but we ended up having a blast. Park is small but exceptionally clean. They have a sea liion and dolphin shows, It is not exactly sea world, but we really enjoyed it. Few water slides. I was happy we did it. I bought the video. My daughter was so jealous my friend gave her a dolphin swim as a gift when we took her to Cancun over the summer. In Cancun, the park is much bigger, but our dolphin experience was way more than what my daughter received.
I think your grandchildren will enjoy it. Have fun.
Sherry