In my case, I need to add coulda-woulda-shoulda to the list of variables. I met my wife at seventeen, just four months into a concerted effort to suppress my gender dysphoria. There was no need, I thought, to tell her of my perversity (what I believed it to be back then), because I thought it to be completely under control. I didn't tell her nearly four years later, when we married (still under control). I didn't tell her even after the births of our two daughters (Dad's in control!). When I did finally lose control, it was the end of a seventeen year suppression - but I still tried to keep control through compartmentalization - so, still no need to tell. Of course, the activity of cross dressing in secret eventually becomes no secret at all - even if not talked about. Our relationship had to hit rock-bottom before we could start to really deal with my gender identity together, which - keeping with a theme - occurred another seventeen years later. As I write this, another seventeen years have passed, and our forty-eighth anniversary is coming soon. Our marriage looks nothing like what it started out as (few marriages do, even without a gender conflict). I'm sure that it wouldn't have started at all, had I come out when we met 50+ years ago, nor would it have survived, had I come out to her at the same time I sort-of came out to myself, returning to the "shameful" behavior of my youth.
I could write a booklet on "How Not to Be a Happily Married Trans Woman." I was a husband who was this such a girl, then that such a girl, and many such iterations in-between. Consequently, my wife has had to make her own transitions throughout this whole process - to the point where she has given up having a husband at all, but she still has "such a girl."