Are you sure that your friends are helping you by accepting your request from their mailboxes under the Help category? Also, please keep in mind that requests may show up with some delays due to the server side communications between Facebook's friend list and us. Is it possible for you to run a test with one of your friend? Here is the steps you can do to run a test;
- Send a request to one of your friend. (Only 1 friend, for testing easily)
- Talk to your friend and ask whether he/she has got the request in the mailbox under Help category.
- When he/she accepted your Help request check your Events menu to see the image of your friend there. Keep in mind that requests may reflect to your game a bit later.
- Refresh your game until the image appears there.
We highly recommend you to try this a couple of times with different friends. Please let us know if you still think there is a problem.
Keep in mind that the friend joining your event must also be playing Fashland as your neighbor.