As far as most liver diseases go, the patient is usually prescribed opiate painkillers by their doctor. I would be almost entirely certain she is on medication for the pain, and if not, she should complain and get on some.
The only thing that's really important is that if she takes a painkiller that it NOT contain any acetaminophen (APAP) or other non-opiod painkillers along with the opiate.
My dad had a liver disease and his first doctor was stupid enough to give him Vicodin. The next doctor realized Vicodin had APAP and was even stupider and switched him to Percocet which still has APAP in it.
Things like OxyFast, Oxy-IR, OxyContin, MSContin, MS-IR, Fentanyl patches, etc. would be fine.
Of course, she may have a specific disease that would not allow for her to take pain medication, so if she doesn't want to talk to her doctor, she should read about it.