The most important bit is that whatever she does on a computer, she saves it into the Syncthing'd folder that I set up to copy into my persistent storage system

The most important bit is that whatever she does on a computer, she saves it into the Syncthing'd folder that I set up to copy into my persistent storage system. Regardless of organization, search, and coordination, step 1 is making sure the data is saved. There's always time to shuffle it around later.