Actually, we don't know that either way.
We understand where her philosophical position takes root. That's it.
On its own that's certainly interesting.
Whether or not there's flexibility in that position, though, is a question that remains unanswered.
Clearly, there is in fact room for compromise with her.
I'm curious, what, in the post, leads you to that conclusion?
Room for compromise comes from the fairly obvious approach of disassociating abortion from her personal circumstances... likely by sharing the author's stories about women he knows for whom abortion was a difficult but justified personal choice, not a spiteful act directed at the woman to shame her for being barren. With some empathetic discussion, this doesn't seem an unreasonable outcome. What more do you want, to believe that there is room for compromise?
Clearly, there is in fact room for compromise with her. At that point, the author could probably have shared his story about women he knew who'd had abortions, for whom it was a painful decision that wasn't thoughtless and casual and spiteful, and wasn't an indictment of her worth. Done carefully, she probably would have acknowledged that it's properly a deeply personal decision and she's not really that committed to her own feelings.