Recovering unsaved Word file minimised to Dock bar on Mac

My daughter worked on a Word file without ever saving it and only minimising onto the Dock. As the file was never saved, just minimised, it has a name like "Document3...". It is no longer on the Dock bar and not in the Bin. Does anyone know which folder these files are saved to when you minimise to the Dock bar?

[Re-Titled by Moderator]