End of the World and Back
She knows (hates) that if it comes to it, she will go to the end of the world and back to be with Cole. He has power over her that binds her heart to him. He possesses her heart and she has his.
She knows that he'll go to any length possible to be together, just as she will. There always has been a part of her that she can't quite control that defies all logic and reason. That part has only been made stronger by her love for Cole.
It tears at her knowing all she does about their relationship and where the might end up (he'[s a demon; can she truly expect to find happiness with him for a lifetime?) and so she tries not to think about it at all.
She can overanalyse the situation for hours, days, weeks, longer, but in the end the answer will be the same: She loves him. She loves Cole. And he loves her.
Isn't it enough that they love each other? (No, her mind tells her, but her heart will not listen. Deluded, her mind believes it to be. But then, they always did say love was blinding.)
Has Cole not proven to her that he is no longer evil and can be trusted with her life and her heart? (Yes, he has, though trust can be broken; trust is fragile.)
She knows there are uncertainties (she has a lot of her own and then there are the concerns of her sisters about Cole and the concerns of Cole himself), but in the end she knows that doesn't matter.
They might or might not make it to the end together, but it's not about the end. It's about getting there and the journey they take. For now she wants to make her way onwards with Cole by her side. It may be a short trip or a long one but every minute of it, she relishes.