Princess Diaries Series:
* The Princess Diaries (2000)
* The Princess in the Spotlight (2001)
* Princess on the Brink (2002)
* Princess Mia (2003)
* Princess Mia and the Royal Wedding (2004)
* Princess Mia and the Royal Baby (2005)
* Princess Mia and the Secret Holiday (2006)
* Princess Mia and the First Impression (2007)
* Princess Mia and the Royal Art Show (2008)
* Princess Mia and the Big Question (2009)
* Princess Mia and the Royal Graduation (2010)
* Princess Mia and the Royal Wedding (2011)
* Princess Mia and the Royal Tour (2012)
* Princess Mia and the Royal Christmas (2013)
Other series:
* "The Royal Diaries" series (she wrote several books in this series about different historical princesses)
* "The Amelia Bedelia" series (she took over writing this series from Peggy Parish)
* "The Misadventures of the Family Fletcher" series (she wrote two books in this series with her husband, Andrew Clements)
Stand-alone books:
* "The Princess Diaries: Royal Wedding" (a novelization of the movie)
* "The Princess Diaries: Royal Engagement" (a novelization of the movie)
* "The Princess Diaries: Royal Romance" (a novelization of the movie)
Note: This is not an exhaustive list of all books by Jude Watson. She has also written numerous other books, including picture books, chapter books, and even non-fiction books.
You can find a more complete list of her works on websites like Goodreads or Amazon.