In the 1990 Batman comic arc "Bride of the Demon" (the first time Ra's & Tim encounter each other) Ra's has a lover named Evelyn. As the evil-secret-lair-base is exploding or imploding or whatever at the end of the story, Evelyn and Talia escape in an aircraft together. Evelyn says she's pregnant with Ra's' baby.
And then. As far as I can tell. She never shows up again. Is never even mentioned again. Talia has an entire pseudo-stepmom and potential half-sibling that just don't get used by the writers.
Flailing about this now because one, I think this has a lot of fanfic potential. Especially during the "Resurrection of Ra's al Ghul" arc if you want Talia bending her morals in an attempt to save her son. Or several years post-canon to give Damian (and possibly Talia, depending on how far out of touch she and Evelyn fell) a surprise relative.
