Frightened Daughter, welcome to the forum, though I'm sorry you have to be here. Your question is one that is asked the most frequently and the one to which a definitive answer is impossible. Hep C and cirrhosis puts one at high risk for liver cancer, bleeding varices, ascites and edema, encephalopathy, and other problems. Age also plays a factor, as do other health problems a patient may have, such as diabetes and cardiac disease.
It is not the cirrhosis that kills a person, it is the problems that develop as a result of cirrhosis. Of course, if one goes into liver failure, then a transplant is needed or the patient will die. However, there are usually a series of events that take place prior to that.
I contracted hep C 40 years ago. I was diagnosed in 1993. Aside from overwhelming fatigue, I had no symptoms. Then, in '05, I was diagnosed with liver cancer. Mayo Clinic saved my life and it has now been almost 2 years that I have been cancer free. I do have mild cirrhosis and a risk for recurrent cancer. I've dealt with ascites and edema, but thus far have escaped varices and encephalopathy. With so many possible problems with hep C and cirrhosis, you can see that each case has to be evaluated individually. Even then, it's difficult to say how long a person will live until they get really, really bad and into liver failure. If you will read some of the educational threads, you will find some answers to your questions. You will also get a lot of support from the wonderful people here.
It is good that your mom follows a good diet. That is of tremendous help. Aside from that, regular followup with a hepatologist and compliance with the doctor's plan of care can help her to live many more years.
Hugs,
Connie