We are glad that you are helping with the decryption of Eliza's secret letter. From our experience with cryptography we understand that Eliza has been used an encryption method in which every page has a hidden puzzle the solution of which should provide a necessary piece of information to solve the puzzle on the next page.
Do you have the solution?
Please try your answer here. The page is password encrypted and you need the third, the twenty-eight and the twentieth word of the text of the final solution to access it (in exactly this order, and please use spaces in between the words and pay attention to capitals).