Possibly than any of the other children, Courtney was treated like her father's baby.
Not to say that he loved her more than the others, but because she had already had an unfortunate start to life, Abaddon wanted Courtney to have the best of everything and never know a single hardship.
Courtney liked that until she got a little bit older and began to feel slightly smothered.
Especially when she wanted to learn how to defend herself at around 14 years of age.
Abaddon was firmly against it, of course.
From his extensive experience, the moment that you develop a skill, the world around you will force you into using it.
That very thought was enough to terrify Abaddon into rejecting his daughter's request outright.
His baby girl would remain safe and without so much as a callous on her hand, or a scratch on her cheek.
It didn't matter that she was already physically invincible.