Thanks Eric. That didn't work exactly but helped me to find a solution. Summary: I set up the Shared Folder on my iMac and gave my wife (and Everyone) permission to Read & Write all the files in that folder. She can successfully access and change them from her MacBook. Then, when I later open the document (newly changed by her) and click on Get Info, I see that my name is no longer listed in the Sharing & Permissions window. After adding myself back to the list I am able to again make changes to the document and save it to the Shared Folder. My wife likewise can re-open the file I changed and still has Read & Write access again, too. Strange, but it appears that after she changes the document my name is removed from "Sharing & Permissions" even though I am the Author of the document and owner/Administrator of the Shared Folder. As a side note, when she goes to "Get Info" on the documents, Under "Sharing & Permissions", it only says "You have custom access". There is no box there to allow her to see/change the priveleges so she cannot add me. I hope this has helped you and others. If you know/think of an easier, permanent fix where I don't have to add myself and reset permission each time she alters the file; that would be great.