Customer's PC erased

I am a small business owner of 2 years. I own a computer repair service,
I provide onsite service, which means I go to people’s houses and fix
their computers & devices. Yesterday I repaired a laptop, and
then I performed their Windows Updates. 1 of these updates
caused a glitch, and their computer is now locked. it is a glitch
affecting only Windows 11 users with Bitlocker. I have exhaustively
researched every possible method of recovery, I am not going to
discuss the technical details here, I have posted that elsewhere.

I cannot fix this lady’s computer, and she has a large quantity
of photos and business documents that are now lost forever, with very little
chance of recovery.

What should my next business decision be for this? Should I take the
laptop to another computer repair store, one of my competitors, to
see if there is a small chance they can recover it? Should I merely
tell her her files are lost, and assist her to rebuild her computer
fresh? Even though I did not cause this glitch, it was caused by an official
Microsoft Update, I was the one who pushed the button.

I do have Professional Liability insurance with Errors & Omissions, but
that is only for catastrophic cases, like a lawsuit. It is not a warranty.

If I take the PC to another shop for a 2nd opinion, there is a risk
they could tell her to sue me. If I do not take the laptop to another
shop, there is a risk that she could sue me because I am alone
in my opinion that I did not cause this glitch.

What is the best business decision here? Thanks everyone!:D

Is the hard drive erased or can you connect it to an external device and copy her files that way?

The files are gone forever. I am not here to discuss the technical aspects of this incident, I have done that elsewhere. I am asking for business advice. How do I prevent the customer from suing me? How do I protect myself with this customer? It is the unknowns that I need the most help with.

Make her an offer she can't refuse before she has a chance to seek legal council.