Theres two types of HRT, one is oestrogen and progesterone for women with a womb. The other is oestrogen only for after a hysterectomy.
Both linked to increased breast cancer rates. Combined one has the recent links to increased heart attack/ stroke rates.
It depends on her GP some are pretty hard line and wont use HRT. I think the best approach is to teach people like adults, tell them the risks and if they wish to proceed with something give it a try. I think the problem is people find the idea of a hot flush a bit amusing whereas in reality they can really be terrible and affect your quality of life massively.
This is a useful site for patient information - link to HRT stuff which is pretty comprehensive
http://www.patient.co.uk/health/Menopause-and-HRT.htm