Aw sad i liked her dynamic, no more theft to worry about though :D.
It's not very intuitive, but I think adding a label to the book is maybe the easiest option? you could make a joke even: "if your reading this, you will need this book!" (Joking about the fact you need to be 2 feet tall to read it, and it contains the solution) idk stupid idea, but a label of some description might work.
I haven't seen the eye effect you added yet, but im sure it will do the job!
Since you mentioned an epilogue, i can't help but think adding a wheatley-esc quote would be funny where pinkie apologises in hopes it somehow reverses her mistake . (Portal 2 has an ending scene where wheatley apologises for his stupid actions during the game). Just an idea but I think it's funny
Not sure what your situation is, but this is really neat, maybe in the future a non- nsfw game could be a thing?