Someone with a uterus and a history of ovarian cancer likely isn’t a candidate for estradiol, but there are other treatments. Maybe estrogen + progestin to prevent unopposed endometrial proliferation. Though I hope OP can find a doctor who can help with hormone replacement if that is what his partner wants.
It’s interesting, it is becoming a modern day contronym
https://www.merriam-webster.com/grammar/nonplussed