Hi Virgina! Your sister is correct, you can go on a pirate treasure hunt right in the heart of Adventureland inside of the Magic Kingdom. This fun interactive treasure raid is called
A Pirates Adventure~Treasures of The Seven Seas. Young and old scallywags alike are recruited to help raid 5 treasures hidden throughout the land, if you are successful in your journey you will become an official member of Captain Jack's crew!
My daughter who is 8 years-old is enthralled with this interactive treasure hunt, while my 3 and 4 year-old boys lose interest rather quickly. Each of the 5 missions take about 20 minutes to complete, but you can stop and start a mission at your own pace throughout the day. I would encourage you to sign up and try a treasure raid with your little one, he may really enjoy all the interactive elements, especially if he is a pirate lover. The sign up booth is located in The Crow's Nest in Adventureland.
I hope you have an amazing time fighting off the foes of Captain Jack. If you have any other questions we can answer for you, just let us know.
Have a Disney Day,
~Jen