keyboard – How do I log in on pre-2017 Macbook Professional & MacOS 13, when all advisable options have failed?

My spouse has what I suppose is a retina Macbook Professional 13″ from about 2015, working on MacOS 13.7.8 (Ventura). When the log-in display screen seems after powering up, the password instantly does slightly jiggle – which (to me) appears related – however her password now not works, though it did final week & hadn’t been modified.

We have tried all the standard options:

• checked caps lock is off, and made certain password is entered with
  right case;
• shut down, waited 10 minutes, rebooted;
• tried with and with out energy adaptor related;
• connected an exterior Home windows keyboard (sure, I do know to make use of Home windows key
  for “Command” & Alt key for “Possibility”) through USB hub related to
  laptop computer’s USB-C port;
• tried different doubtless password permutations;
• efficiently used “reset password” operate to reset PW through Apple ID
  log-in: “Your FileVault quantity password has been reset”;
• again to log-in display screen: unsuccessfully tried new password;
• adopted Apple’s directions to aim MacOS Restoration: the Restoration
  display screen fails to look & it simply goes straight to the log-in display screen;
• adopted directions to entry the Accessibility Keyboard. No
  keyboard seems; as a substitute, it goes to the log-in display screen and I hear
  “voiceover on”, however the cursor stays unchanged once I say the
  person’s title;
• adopted Reset {Hardware} Controllers directions: the method fails
  to start out;
• adopted Reset SMC With out Keyboard directions: once I reconnected
  the ability adaptor, the laptop computer instantly began up with out me
  urgent the “On” button, the Apple brand appeared, and some seconds
  later I used to be again on the log-in display screen;
• tried holding down Alt after Apple chime: again to log-in display screen;
• tried powering up with a number of permutations of “R”, Command, Possibility,
  Management, Shift, and in addition tried spamming the keys.

There was one momentary glimmer of hope: with some severe key spamming, one among these variations introduced up the Reset Password web page and within the high left nook was a 3-item menu with “Begin-up Disk” (or one thing comparable). I chosen this & was given the choice of resetting the PW, which I did. Alas, pointless.

My guess is that

1. the OS cannot recognise the brand new password as it will have to get previous
   the log-in stage with a view to entry the web and get the Apple
   ID modifications;
2. there is a delay earlier than the OS recognises the exterior
   keyboard and this prevents the assorted “press energy button then
   instantly maintain down &/or spam the keyboard mixture” makes an attempt;
3. both the outdated {hardware} has developed compatibility points with Large Sur,
   or alternatively there is a bodily drawback with the inbuilt
   keyboard.

The underside line is that I’ve tried all of the options I can discover inside SE Ask Completely different and extra broadly on the web. And I reside in a small regional city an hour’s drive from the closest main city centre and about 20 hours from the closest Apple centre, so taking the laptop computer to an skilled Mac technician is problematic.

Is there the rest I ought to attempt? My spouse has some valuable private & household information on her laptop computer. Please assist!

UPDATE 1: within the Reset Apple Password display screen, I clicked on Begin-Up Disk & tried altering the PW (made no distinction) – however the display screen gave me one important bit of information: it is working on macOS 13.7.8.