Viola spends years in denial of the fact that Alec is grooming their daughter until Isabelle, age fourteen, tells her about the first rape—after which she knows but blames Isabelle for what's happening.

That depends on who you ask, but the real answer is that she was twelve. Alec abused Isabelle in ways he could deny were sexual due to their lack of resemblance to traditional sex from twelve to fourteen, which is when he raped her and when Isabelle would say it started.

As far as I know I don't think that's Cy's thing! Probably not Lynn's either. But Isabelle certainly has the uhhh. parental issues for it

Sure is!

Viola didn't want to have Isabelle in the first place, and would have preferred an abortion. Alec talked her out of it pretty easily, but months later when Viola developed pretty severe eclampsia (featuring hallucinations and seizures) during the pregnancy, his methods of denying her an abortion became more coercive. This culminated in Viola giving birth in critical condition, and Alec took newborn Isabelle and left Viola to recover without so much as a visit.

Viola absolutely resents Alec for this, but she also sees Isabelle as "that thing that took my husband's attention and love away from me when I needed it most." Not to mention that Isabelle is at the center of Viola's most traumatic experiences. Alec uses this as a means to drive a wedge further and further between them over the years to enable his abuse of Isabelle. Jealousy is his favored tactic, as well as strategically activating Viola's trauma to make her want Isabelle as far from her as possible.

Isabelle is pansexual and panromantic, although she's a little slow to fall in love. She has some issues around her attraction to women, though, and tends to downplay it because she views it as doomed for one reason or another.

She sure does! In AUs where Isabelle comes to the States she tends to do so as a young adult, so she retains the accent. In canon, she stays in England.

Sure! Emphasis on the "general", I'm assuming, so I'll gloss over some detail. Isabelle was born to an aristocratic couple in England consisting of Lord Alec Underwood and his wife, Viola. Isabelle grew up hated by her mother and doted on by her father, but he became increasingly physically abusive and eventually sexually abusive. Their relationship was a very intense, psychologically manipulative one to the point that when Isabelle eventually escapes him, she still looks back on him with more love than anything...at least at first. She does end up realizing how fucked up everything was, but needless to say the environment she spent the better part of two decades in did a real number on her psyche.

Isabelle's a masochist more than anything else! She loves pain in a WIDE variety, from impact to electro to cutting and burning. She also takes great pleasure in being objectified and degraded, treated like she exists for nothing other than her Dom or Domme's pleasure. Other kinks include drowning play, voyeurism, and Daddy/Mommy kink.

Isabelle likes red the most! But if you asked her, she would probably tell you some kind of pastel.