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Thank you for writing and I understand your concern. Usually smoking does not lead to such smell from vagina, it has no direct link with the vaginal odor, neither cancer causes any smell so do not think about these conditions. The smell and itching are due to infections like gonorrhoeic, chlamydia, and candida. Do not worry it can be treated. Ask her to apply Clotrimazole ointment over the vagina once a day before sleeping for five days (consult with a specialist doctor, talk with him or her and take medicines with their consent). Does she have any rashes or discharges from the vagina? What type of an odor does she have, is it sweet or fishy?