They are also random drops sometimes when you are exploring the islands.

you have to buy them with your island coins. in the shop menu you can see a little coin icon and purchase them there

Some islands have treasure chests near the shore, they will be glistening. It costs one shovel to open them and not all islands have them in my experience.

If you are at the home island, you must click on something for her to do and she will sort of teleport there. If you are on an island in one of the archipelagos, all you have to do is click the ground somewhere.

she just stays there

You have to build the incubator, then you can produce aloe.

They are random drops when you are exploring the islands. You can also purchase parts using the special coins that drop on the islands.

I believe you can buy them if you have enough of the jems...

What the heck is this all about? I'm done with all quests. The only thing I have to do now is the islands. However you only want me to play every other day, if that? That is ridiculous! Until I get to the next page of islands there's nothing for me to do. I guess just stop playing....

Archipelago #2 island 5

If the required item you're talking about is spider legs, you have to complete the main quests until all of the eggs are cleared past the door that's by the spider tomb. The cave will have spiderwebs and eggs by the entrance. It'll take 10 food for 2 legs.

I've been wondering this as well. Did you find it yet?

I think you should click on you boat after going back to your island and then on the box on your right. Click on your item and then ''send back to barn''.
It will pop on your warehouse and you'll be able to use it.
(Sorry if some words are not the same, I use a French version).