From what I understand it’s an individualized decision made with your GYN - I recently started HRT at age 68, even though I was 11 yrs post menopause - my GYN and I took in all aspects of risk factors - cardiac, breast cancer, etc.. and although I have a sister who died from stage 4 breast cancer, she was a half sister so we share a mom but there was no breast cancer on my moms side of our family tree. Also I needed to be cardiac tested - I have no visible signs of cardiac disease but was ordered a cardiac calcium ultrasound to determine if there was disease I may not be aware of . After all that, my GYN Dr brought my case to the board at Yale hospital to ask for further opinions because I am so far post menopausal and that is one of the possible risks. I too was still having awful frequent hot flashes and have significant osteoporosis of the spine. I would have a discussion with your GYN and see what is possible in your situation, but obviously the history of breast cancer in your mom likely could be a problem. Good luck!