Was she born with a uterus?
What defines a human? Merriam Webster states that a human is "a bipedal primate mammal". But a baby doesn't walk yet, so it crawls. Is it not human?
No, that's fucking stupid. We define humans as a bipedal primate because that's what we are, even if not every single fucking one of us is bipedal at every moment in our lives, we're still human. If a person loses both their legs, they don't become not human. They're still the thing they always were. If your wife was born with a uterus, or was born with a body which should - barring genetic abnormality or environmental interference - have one, she's female. If disease or surgery damages or destroys/removes her uterus, she's still female just as she's still human if disease or surgery damages or destroys/removes her legs. And if you push enough testosterone into her that she grows more hair and bigger muscles, she's still female then as well.
She's welcome to identify as and live as whatever she chooses. If she feels happier identifying as a man, taking male hormones, dressing as a man, and acting as a man, then more power to her. If that truly makes her a happier human being, I'm behind her 100%. But biology still fucking exists. She still has the bone density of a human female. She still has the hippocampus of a human female. She still has the pelvic structure of a human female. She still has the genetics of a human female. Biology still fucking exists.
I don't understand why this is a point of contention: biology is a real fucking thing. It's reality. Why it is that radical trans activists are as Hell-bent on denying basic scientific facts as the anti-evolution, anti-climate change right is beyond me and absolutely fucking infuriating. Bunch of fucking flat-Earthers. But somehow people with a university education, who are even TEACHING at universities, have CHOSEN to deny fucking BIOLOGICAL FACTS because those facts make some people sad. Reality doesn't give a FUCK about your FEELINGS. That applies whether you feel sad that humans and earthworms share a common ancestor or whether you feel sad that taking some testosterone blockers fails to alter your underlying physical structure.
If a biological male is happier living as a female or vice versa, more power to them. But the denial of basic scientific fact is leading us into a fucking DARK AGE where progress halts because feelings replace facts and we all become convinced we get to live in our own special reality. Reality doesn't fucking care about your feelings. Reality is what continues to exist even when nobody believes in it. And it will be the death of us as a species to continue down that road because you can't solve major problems if you can't live in reality.