What happens to Pip’s sister?

In chapters 13-23, what is the main thing that happens to Pip's sister? What are the details? Maybe there is a lot that happens to her, if so, what is all that happens to her? If someone asks you: In chapters 13-23, what happens to Pip's sister? would you answer with: She was attacked? If so, what are some of the details of her attack? Thank you to whoever answers. :)