I started taking spiro, estrogen, and progesterone 3 months before my 42nd birthday. Now, at 14 months HRT, I almost have aa-cup breasts forming. I have visible cleavage, and I've been told my face is rounder now (I haven't noticed this myself).
It was probably 5 months on the above combination before I started seeing cleavage. At that point, it was leaning forward with the weight of C-cup breastforms glued to my chest. But also, the above combination started making my nipples sore at about 3-4 weeks.
I had been married for about 21 years when I came out to my wife. Last September, we celebrated what we knew would be our 23rd and final anniversary. So, I can appreciate the anxiety around transitioning while married.