I think your doctor is exactly correct in not telling your mum a timed prognosis. I believe no one can predict how long someone will live and how she will react to the treatment. Being healthy is a big plus. If she maintains a positive attitude, gets good care and is paying attention to what her body needs, she has a good chance of beating this back. I know because that is what I have done.
I was diagnosed with Stage IV, nsclc, adnocarcinoma, 31/2 years ago, 2 weeks before I turned 50, and I am doing great, great, great!. I had a tumor at the top of my right lung, but also had mets to my bones, liver, lumph nodes and brain. (diagnosed when my left leg broke). My first scan after finishing my chemo and radiation was totally clear. I went into remission on Iressa for 1.5 years. It reoccurs every year or so on my liver, I do more chemo and it clears up again. I am now doing chemo on a schedule with more weeks off between treatments as maintenance and will do this until they come up with another Iressa that works for me. I feel great but do get a bit tired on some days especially after chemo. I have shortened my work hours this year (hard for a type A person!) so I can enjoy life while I do feel great. I am planning trips to Switzerland and Paris this year. And I fully intend to be around for a long time.
The statistics are horrible for this diagnosis but remember they include the people who were wheeled into the hospital and were not otherwise healthy. I fully intend to beat all the statistics and more of us are doing so. On the other hand, it is striking more women and more non-smokers. I have a huge support group around the world. My husband (who does get scared still) and I put out a regular email to be open about what we are going through and how others can take comfort from our positive experiences. Having the best oncologist in the world helps!
Your mother needs to let anyone who want to help her do so. My friends fed my husband, babysat me when he worked, slept on my floor so he could get a good night's sleep, and on and on. She needs to eat as well as she can to maintain good nutrition and not only get rest but keep excersing as well to keep her body fit.