Post menopausal discharge should not be taken lightly. She should go to gynaecologist for physical and pelvic examination. Pap smear  blood sugar and ultrasound is must. Doctor will also rule out any leucoplakia vulva along with monilial vaginitis. Antifungal tablets orally or vaginally can be given. Vaginal wash also helps. Don't use dettol .salon, medicated soap as they can worsen the problem.

I agree with the comments made so far. Besides, it is advisable to undergo procedure of dilatation and subject the collected water for investigation. Apart from this Gynaecologist can subject for hysteroscopy and related procedures.

Hello there...I can understand your concern. If would have been better if you had posted what the doctor had diagnosed. Whitish vaginal discharge and itching usually point towards vaginal candidiasis. It is very common among women. Kindly consult a dermatologist once for further evaluation. They will examine her and advice further management.