The possibilities depend on a few things such as her ability and willingness to purchase and learn software, or spend lots of time manually dragging and dropping files into folders.
If I had all files, I would use Photo Mechanic to create whatever folder structure I wanted and move the files into that folder structure. Setting that up in Photo Mechanic and starting that file transfer would take about 3 to 5 minutes because I know Photo Mechanic and do this often. Then the software would do the work on its own and the time it would take would depend on the number of files, but even 100,000 files would probably take 30 minutes.
DIY is not always less expensive. If she were my client, it would cost her more for my consulting time alone to discuss the options than to have me do the work!