My father was just diagnosed in June with Stage 4 RCC with mets to his brain and lungs. He went though 14 brain radiation treatments, and his current CT and MRI brain scans appear stable at this time. We are very grateful! He is also back on Sutent after a month off (he had blood clots in his lungs and was found to be severely hypothyroid). I would encourage you to make sure your wife's blood counts to be monitored, as well as keeping an eye out for her thyroid levels.
As far as side effects, he experienced extreme fatigue, slurred speech, loss of appetite, feeling cold, and weakness, but we think a lot of those symptoms might have been due to his low thyroid function in addition to the Sutent.
I wish you both the best,
Julie D.