Unfortunately only the books she recorded with Full Cast Audio are avaliable for listening. Anything recorded with Penguin Random House, such as The Lioness Quartet and the Protector of the Small Quartet, are not present.
I'm looking for fantacy and sci-fi young adult books to listen to if anyone has suggestions, there are practically none in the new "word" category, which is mostly filled with poetry and classics. Adding podcasts to spotify was a great idea, if the same was done for audiobooks and there was a push to get new books onto the app then I would subscribe to Spotify for life. Other audiobook apps are unweildy, expensive, and/or have a poor selection. Spotify has the potential to be none of those things!