What was Evelyn’s “condition” referred to a long time ago and how did it matter to her pregnancy? I don’t know if it was ever elaborated on.
I've touched on it a few times, but it's buried in my blog somewhere.
Basically, Evelyn has a condition where her bile sack is too large, giving her an extraordinary power source compared to other witches.
However, this is a curse in disguise of a blessing. Her bile sack is too large, but her body (like any witch) aren't built to compensate for that amount of power. So using too much magic exhausts and fatigues her.
She "turns gray" and starts freezing when her body needs to recharge, she needs time to recover by resting, and it can take hours to days.
Lethargy creeps on her, and it has affected her relationships and how other witches view her. Some think she wastes her powers, some think she's lazy, some believes she hasn't earned anything she's worked for because "she's powerful." Resulting in having no friends and a very small circle of people who she interacts with in the demon realm.
Evelyn's condition means that her bile sack sucks out any life from the baby in her, using it as a "spare battery" when she's exhausted. The stress about using any magic during her pregnancy would also contribute to the lack of successful full-term. Her bile sack would use anything in her body to "steal" from to heal faster.
The way it impacts her fertility is due to how (in my version anyway) magic is part of what brings something life (light) during pregnancy.
So that's why being born without magic is shameful and disgraceful. You lack connection to the world around you, the Titan, where magic is in everything (As Eda says to Luz, how in the old days that witches interacted more with the land).
But Caleb is human, and thanks to his human genes contributing to their baby's DNA, their baby builds an immunity to her bile sack's parasitic design. It survives, because that's what humans do - They adapt, survive, and overcome.
This is something Evelyn has always loved about humans. They're not relying on magic, yet they somehow make it through. And it is something she loved about Caleb, too. No matter how rough and hopeless things got, he always cheated his way out somehow.
But you can only cheat death so many times until you gotta pay your tab. But, hey... Resilience goes in the family, doesn't it? :3
