Here’s an observation I picked up from working on my essay.
There’s a moment in A Feast for Crows when the twins are arguing about Tyrion. For TV-only peeps: this is a major divergence from the books.
Cersei doesn’t know Jaime freed Tyrion. They’re arguing about him, early in the book, and Cersei thinks the Tyrells are helping him. She mentions the possibility of him being on his way to Highgarden as they speak. Jaime says: no, he’s not going to Highgarden. And Cersei just keeps on harping on where Tyrion might be. It doesn’t occur to her to ask Jaime: wait, what do you know about where Tyrion’s going?