Hi I would say the last thing she needs is a replacement I had similar issues and had arthroscopic surgery but I did this privately through insurance, I believe the cost at the time was around 100k THB but certainly worth looking round
in my experience you need the owner of the house to accompany you with the blue house book, a letter from immigration as prof of residency along with passport & visa. I have done this in Phuket & later in Buriram but Buriram was after I revcieved my Permanent Residency so no immigration letter needed.