You can't, but you can follow up on it. Remember what Nancy said about the slit she just noticed in the tent?
Hint 2
Leave the tent and turn left to look at the hole from the outside. Hmm ...
Hint 3
Me, I'd rummage around in the sand with my hands, but Nancy is fastidious and demands a tool --
Hint 4
-- so use the shovel (from main room table) on the sand till you find something that tells you where the amulet might have gone. It's going to be in a random spot, but you'll find the shoveling slightly easier if you start from the top left and work right and then down.