Where are my files from Windows 11?

I migrated my wife's PC after a forceful Windows 11 update to Linux. I made a backup of her files by doing an rsync of almost the complete C: drive onto an external drive formatted with exFAT. This was a grave mistake.

After the Linux installation we noticed that several files were missing and older files were back. My current guess is that I was somehow copying from an old snapshot instead of the current state.

I rsynced everything except for the Windows folder. Does anyone know if there is any chance of getting our filea back? Amd what actually happened?