The Lost Adventures have already been released, they are not the Book 4 continuation you are searching for, however, the answer is: We can't be sure. I personally believe that he likely will, and he will help her put her on the "right path." If Bryke really wants to be realistic, and please me, she will escape, eventually crawl out of her sanity, and hunt them, making her an antagonist and continue their story. However, knowing Bryke, this is highly unlikely. So, we can't be certain, but it's very likely.