Will there be an opportunity to get Jezera pregnant in future?
Getting demons pregnant, or vice versa, is extremely hard. Half-demons still have some issues presumably. Not impossible of course, and this is a setting where ostensibly you can rewrite your body to allow for easier pregnancy, but it seems very improbable for a variety of reasons. Of course, this is still a game and the writers have altered the story when something really popular reared its head.
It would however be a complete disaster for everyone involved. She's a twisted psychopath with a powerful hold on Rowan, and she absolutely does not want to get pregnant with him as the father, far as I can tell. Hell she doesn't want to be a parent either, just keep enjoying her sex and luxuries without a care in the world.
To actually answer your question though, the writers haven't given any indication as to this happening.