I have to agree with you and I think the above picture is funny. Of course there is not need for physical abuse or slapping a woman but it's the analogy that is still good. Sometimes you do need to keep them in line, let them know who is boss. No matter what your momma told you a woman does respect authority and wants someone in charge.
Man up and dont tell her. LOL If she finds out it's NONE of her business unless she agrees with you.
When I told my woman I was doing HRT she did her own research. When I mentioned Deca she again did research and only concern was Deca Dick and how we would deal with it. NO problems there.

Keep on the HRT...
If she is not open to discussion or listening to your views on this then realize there will be a LOT bigger problems down the road...