I'm really wondering why the author bothered to have her go "back in time". Was it just because that particular element was popular when he started? Generally, the characters use their knowledge of the future to change their path or get ahead of fads and events. Here she only knows one thing: the Count and her family are dangerous. And she didn't need to go back in time for that. She knows nothing about the kingdom, since she was trapped in a tiny house with no interaction with the outside or education. She knows nothing about future events. She doesn't even know why the Count captured her. And because she's emotionally stunted, she doesn't behave like an adult either.
The story would be exactly the same if the Count had taken her to her house, abused her for a week, and she escaped instead of stayed there for over ten years. Then the story could pick up at the same place as in chapter 1, with her running into the prince on the street while running from the Count. Her behavior could be the same, her knowledge would be the same, everything would basically happen the same way. Only without the reincarnation element. I even think it would be a better story for it. But maybe he thought he couldn't sell the story if he didn't add the "back in time" tag.
On a separate note, who exactly was feeding her all that time originally? She said she spent days on end alone in the cabin, but there's no mention of what she ate when the Count didn't show up. She's too young to know how to cook, and he doesn't strike me as the type to cook either.