Direly fucked up story, naturally, but here goes.

The April after Isabelle turned fourteen, Alec had a business trip that would take him away from the house for about eight or nine days. The day before he was set to leave, he and Isabelle went out together and had a great time, and then came home and went to bed together as usual. Isabelle was in the process of dozing off when she realized that Alec was touching her in a way she wasn't used to, and when she opened her mouth to ask him what he was doing, he just pressed his hand over it and kept going.

He didn't say a word. No reassurance, no praise, no explanation, nothing. The only thing Isabelle could think, based on the way Alec had talked about his other rape victims previously and her own awareness that this was rape and several mortal sins stacked on top of each other, was that she'd done something wrong and that he didn't love her anymore. The trauma of what was happening and of losing Alec's love sent her into dissociation, and by the time she came to in the morning, Alec was gone.

Isabelle spent the next few days alone, trying to cope on her own, but eventually emerged to tell Viola what had happened. Viola screamed accusations and blame at her, shoved her into a rosebush, and had her locked in her bedroom and starved until Alec returned. When Alec did come home and found Isabelle starving and dirty he force-fed her, showered her, and then explained to her that what he did to her was an act of love. Isabelle embraced this as the truth rather than go on thinking that Alec didn't love her, because as long as he loved her, she could believe her life still had meaning.

From then on Isabelle clung to the belief that Alec loved her no matter what he did and that his abuse of her was just an expression of that, which Alec used to manipulate her into accepting continual rape for the next few years. I feel like this probably explains a lot of her psychology, and I hope you find it so too. :]