Hi venkatesh , welcome to healthcare magic, Iam Dr.SIVAYOGI, I am from the same locality chittoor, As per the details you have given, the pills your mother using now contains oestrogen hormone and progesterone hormone known as oral contraceptive pills. But at this age the most possible reason for using those pills will be excessive menstrual bleeding known as dysfunctional uterine bleeding .As because she may be approaching towards her menopause.if you would have mentioned her age I would have given further information. If any thing it requires for future information you can directly contact on my profile. Regards DR.sivayogi MBBS MD