Is Tarceva right for my Mom?

My mother is finishing up her radiation and chemo treatment for stage 3a NSLC. She smoked for 45-50 years (she's 67 now) and she quit smoking 3 years ago. She was originally diagnosed with stage 1 last year and they did a partial lobectomy on her right lung and felt they did not need to do further treatment. On a routine scan, they found a cancerous lymph node, so they did 7 weeks of radiation and 4 rounds of chemo. Her recent scans came back clean and now she has the option of taking Tarceva to hopefully ward off any future tumors. She is in really good health, has tolerated everything as well as possible.
Can someone share any experiences they've had with Tarceva and its effectiveness?
Thanks!