On Nabooti Island, at Blue Nile Falls, you can only reach the hidden cave by helping the woman with her animals.
(Take the chicken across, come back for the fox. Drop the fox on the other side, but bring back the chicken. Leave the chicken on the right, and take the feed across. Now go back for the chicken.)
you dodge them
Go into the Nabooti museum and talk to the tour guide at the Nabooti totem.
If you are really lost go on youtube and search poptropica nabooti island it should help you
She directs you to a cave on the right side, which is partly hidden by a bush. Inside you can find the Purple Jewel.
Go to the museam in Nabooti and put the jewels in a certain order.
when you go to nabooti island pass the boy on the platform under you.then you go to the left. when you see three people in a row you are at the store.
Find the bush that is on a rock in the right side of the falls. Go behind it to find the cave that has the Purple Jewel.
In the museum as you first enter the island. Go to the Nabooti totem pole and accept the challenge.
you take it back to Nabooti and go to the merchants and trade it for a camera.
Go up
Once the woman and her animals have crossed, you can go to the right side of the falls and move the bush on a rock there to reveal a cave. Inside is the Purple Jewel.
You can go to youtube.com and search nabooti island. Then it will show lots of walkthroughs, but choose the one that the user poptropica made.