Spots on the lungs other than cancer are called solitary pulmonary nodules which are oval shape or round lesions seen on the chest x-ray and CT scan. These spots are benign. One reason is inflammation of the granular tissues due to infection on the lungs. This infection can be due to fungus like Cryptococcus, histoplasmosis, coccidioidomycosis and aspergillosis. TB (Tuberculosis) is other condition which causes spots on lungs.
These spots or solitary pulmonary nodules can also be due to some other diseases like rheumatoid arthritis or sarcoidosis. Chest injury can also result in to lung spots.
Another common non cancerous spot in lungs is hamartoma which is a clump of tissues.
After confirming spots on lungs by x-ray or CT scan, a repeat CT scan is recommended after every six months for 2 years to know the growth of the lesion. If spots don't grow in size for the 2 years then these are noncancerous.
Don't think about lung cancer yet....it could be nothing...I wish her luck.