Kidney tuberculosis is not infectious, but, as you've been told already, tuberculosis of the lung can be present at the same time with tuberculosis of kidney.
If the lung lesions were confirmed (chest x-ray, sputum analysis), she is infectious for her environment cause the tuberculosis bacillus (germ) is transmitted only through air (not through urine).
To become infected, a person usually has to have frequent exposure to someone with active TB. For example, spending several hours a day with a person with active TB would put you at risk of infection.
Weak immune system, is the most important risk factor for TB infection and TB disease.
Does she take therapy for tuberculosis?
