No. Sarah J. Maas put in a great deal of effort to create the Throne of Glass series. She developed a detailed and immersive world filled with magic, political intrigue, and adventure. The story has its own mythology, history, and set of rules. Fanfiction, on the other hand, is usually based on an existing work and modifies or expands on it. Throne of Glass is an original creation and not a fanfiction.
No. Throne of Glass is an independent work. It has a distinct style and narrative. The author, Sarah J. Maas, likely drew inspiration from various sources like mythology, history, and her own imagination, but not from fanfiction. Fanfiction usually takes elements from an existing work, and Throne of Glass has its own independent identity.
Yes, Throne of Glass is considered a YA novel. It has all the elements typical of the genre, like a young protagonist, coming-of-age themes, and adventure.
One great Throne of Glass fanfiction is 'Aelin's New Adventure' which takes the characters on a journey not explored in the original series. It really delves into the relationships between the characters in a new and exciting way.