This is a list of all the books mentioned/quoted/referenced in Saving Grace, in order of appearance (as well as the number of times it was mentioned/quoted/referenced throughout the rest of the book).
————

The Chronicles of Narnia series by C. S. Lewis (x7)
[Grace mentioned in passing that she finished reading it in Iron Man 3, then, at the beginning of Age of Ultron, it's mentioned that she was rereading it. In Civil War, Grace told Peter it was one of her favorite series. Then, in Homecoming, Edmund Penvensie was listed as a hero who made bad decisions during Peter and Grace's text conversation. Finally, she (and Sai) did the whole, "For Narnia! And for Aslan!" thing three times before battles/fights (in Age of Ultron, Infinity War, and Endgame).]

The Hunger Games by Suzanne Collins (x6)
[Grace mentioned wanting to read it at the beginning of Iron Man 3, and was most likely later actually reading it. Later, in the same movie, she introduced herself to Harley as Primrose. In Civil War, she listed it to Peter as one of her favorite books. Then, in Homecoming, Harley referred to her as Primrose three times.]

Harry Potter series by J. K. Rowling (x3)
[Tony mentioned getting her a box set in Iron Man 3, and Grace told Peter it was one of her favorites in the hotel room in Civil War. Then, in Homecoming, Grace called herself "The Stark Who Shall Not be Named" in her voicemail.]

King Lear by William Shakespeare
[According to Killian in Iron Man 3, Trevor Slattery's King Lear was the toast of Croydon (wherever that is).]

Catching Fire by Suzanne Collins
[Grace was reading it in the hotel in Iron Man 3.]

Prince Caspian by C. S. Lewis (x2)
[Grace was rereading the book in Age of Ultron during the party and later quoted it to Peter when talking on her balcony the second time in Homecoming. I didn't count this with the series as the book was mentioned by name and quoted directly. This also goes for Anne of the Island.]

Romeo and Juliet by William Shakespeare (x2)
[Grace assured Sai a blast was just 'a scratch, a scratch' in Age of Ultron. Then, she mentioned it in her and Peter's text conversation in Homecoming while he and Ned were tracking bad guys. She used it as an example of heroes making bad decisions. Oh, what a mess.]

The Fault in Our Stars by John Green (x5)
[Grace told Peter it was one of her favorites in the hotel room in Civil War, and it was mentioned again in their text conversation in Homecoming while Peter and Ned were tracking the bad guys (Peter asked if he was more Augustus Waters or Quentin Jacobson) and then in multiple instances of Peter reading it in the same movie. Finally, Ned himself referenced it in connection with the text conversation to Grace in a voicemail, again in the same movie.]

Anne of Green Gables series by L. M. Montgomery
[Grace told Peter it was one of her favorites in the hotel room in Civil War.]

Jane Eyre by Charlotte Brontë
[Grace told Peter it was one of her favorites in the hotel room in Civil War.]

The Great Gatsby by F. Scott Fitzgerald (x11)
[Peter said he liked it in the hotel room in Civil War, Grace reread it in Homecoming, Peter said pools weren't his thing in the same movie, prompting Grace to say the book scarred him for life, she later drew scenes from it, Peter gave her a necklace with a quote from it on it for her fifteenth birthday in the same movie, Grace put on the reference necklace and then hid the actual book away after Peter got dusted in Endgame, she wished she could reread it without being sad, then reread it again in the same movie, wore the reference necklace, and then the necklace was mentioned one final time, again in the same movie. I'm only surprised that the number isn't higher, to be honest.]

Oedipus Rex by Sophocles
[Grace mentioned it in her and Peter's text conversation in Homecoming while he and Ned were tracking bad guys. She used it as an example of heroes making bad decisions. This one is, "Oh, boy," on so many levels, and not in a good way.]

Orpheus and Eurydice by Unknown
[Grace mentioned Orpheus as an example of heroes making bad decisions in Homecoming.]

Le Morte d'Arthur [The Death of Arthur] by Thomas Mallory / basically just the legend of King Arthur
[Grace mentioned it in her and Peter's text conversation in Homecoming while he and Ned were tracking bad guys. She gave it as an example for a legend.]

Paper Towns by John Green
[Peter mentioned it in his and Grace's text conversation in Homecoming while he and Ned were tracking bad guys. He gave the main character as an example for a typical male YA character, asking if he was more Augustus Waters or Quentin Jacobson.]

Pride and Prejudice by Jane Austen
[Grace mentioned reading this in Homecoming.]

Anne of the Island by L. M. Montgomery
[Grace was reading this book while waiting to call Peter back during their fight in Homecoming. I love the little Gilbert just lurking in the background on the cover.]

If You Give a Mouse a Cookie by Laura Numeroff
[Morgan mentioned this story in Endgame, when telling Grace what story she could read to her before bedtime. This book was definitely a hand-me-down/gift from Grace.]

Northanger Abbey by Jane Austen (x2)
[Grace read this book and painted a scene from it in Endgame.]

Gulliver's Travels by Jonathan Swift
[In Endgame, Tony called Scott "Lilliputian," which is the name of the very tiny people Gulliver meets on his travels.]