Catherine Doyle and Katherine Webber are both bestselling and award-winning writers of YA and children's books. In addition to cowriting the Twin Crowns series, they are sisters-in-law.

Katherine is from Southern California and spent much of her childhood in the Palm Springs desert. She is the author of Only Love Can Break Your Heart and The Revelry. For younger readers, she cowrites the Sam Wu Is Not Afraid and Dragon Realm series with her husband, Kevin Tsang. She is currently based in London with her husband and young daughters.