@findtheanswersdn
For bones, estrogen mainly works by slowing bone loss, helping maintain bone density.

If interested, here is a link for FDA panel discussion:
https://www.fda.gov/patients/fda-expert-panels/fda-expert-panel-menopause-and-hormone-replacement-therapy-women-07172025
From what I understand,

Breast cancer risk appears lower and more nuanced than older boxed warnings suggested, especially for estrogen-only therapy in women without a uterus. Unlike cardiovascular risk, breast cancer risk is more influenced by type and duration of therapy than by timing of initiation.

Cardiovascular risk depends largely on timing - lower if started before age 60 or within 10 years of menopause, and higher if started later. Transdermal estrogen tends to carry fewer cardiovascular and clotting risks than oral forms.

Starting HRT after age 60 or more than 10 years postmenopause carries higher cardiovascular and clotting risks, so cautious, individualized treatment favoring lower doses and transdermal routes is recommended.

The panel emphasized that formulation, route, and dose all influence breast cancer and cardiovascular risk, with transdermal and lower dose regimens generally safer.