Could her pain be due to arthritis? that kind of pain would kill a critter's appetite.

There might be treatment for that.

You might try asking Dr Robinson what he would do if it were his cat.

Another question I have asked is: "If I decided to put my cat to sleep, would you say it was an inappropriate decision?"

These questions sound unfeeling...but they enable a vet to reply honestly, without deciding for you, if you know what I mean.

Love Mimi as much as you can! Maybe a well-protected heating pad would help her pain.

hugs
Catty1