Did she or you make other changes to the logins ?

Were they removed on all other devices that are connected to this Sync account?

Firefox 80+ has a logins-backup.json file in the profile folder that can be used in case of issues with logins.json or to undo an accidental delete/update of a password. You can check if you can find this logins-backup.json file in the profile folder or in a backup.

Make sure to keep a backup of the current logins.json and logins-backup.json before replacing logins.json with logins-backup.json with Firefox closed.

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page (Root directory).

• Help -> More Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

You can look a utility to browse System Restore points to see if you can recover a logins.json file if you do not have any backups.

• https://www.shadowexplorer.com/
• https://www.nirsoft.net/utils/shadow_copy_view.html

No, we didn't make any changes except she deleting the passwords thinking it was her account.

I am using a fresh install of Windows 11 I tried Shadow Explorer but it didn't help.

I will try to use another computer that was not connected because now when I look at the logins-backup.json it is the same as the logins.json, so it sadly seems that it already synced. I already knew from my FF on my cell phone :'( but it was worth a shot.

Thanks for the help, I will update the thread when I try an offline laptop.

Hi again everyone, I was able to store a copy of logins.json and logins-backup.json.

When I started, FF synchronized (expected), I then attempted to overwrite the logins.json but it synced again.

Any advise?

Thanks

No can do anymore once sync happens anything previous is wipe clean. And if the jason backup doesn't work then it's lost data at this point.