NEW YORK — President Joe Biden's sister, confidante and longtime political strategist, Valerie Biden Owens, has a book deal. 

Celadon Books told The Associated Press on Thursday that Owens' "Growing Up Biden" will come out April 12 of next year. She is expected to cover everything from her childhood as the only girl among four siblings to her "trailblazing, decades-long professional relationship" with Biden, who has referred to Owens as his best friend. Vogue magazine last year dubbed her "The Joe Biden Whisperer."

The 75-year-old Owens has been working with her older brother for virtually his entire career, dating back to high school in Delaware. She managed his winning 1972 run for the U.S. Senate and his unsuccessful presidential attempts in 1988 and 2008 and was a top advisor for his election to the White House in 2020. She also has been closely involved with his own family, quitting her job as a teacher and moving in with him for four years so she could care for his two sons after he lost his first wife and 13-month old daughter in a 1972 car accident.

"Valerie Biden was the cornerstone that allowed me to sustain and then rebuild my family," Biden wrote in "Promises to Keep: On Life and Politics," published in 2007.

Financial terms were not disclosed. Owens was represented by Javelin, the Washington, D.C.-based literary agency where other clients have included former FBI Director James Comey, former National Security Adviser John Bolton and former House Speaker John Boehner.

Celadon Books is a division of Macmillan Publishers, which in 2017 released Joe Biden's "Promise Me, Dad," about his son Beau Biden, who died of brain cancer in 2015.

"Our family's story is a very American one — full of joy but also shadowed by tragedy," Owens said in a statement. "What we Bidens learned long ago is a timeless lesson: that family matters, possibility can emerge from pain, and the ties that bind us together are stronger than anything that might pull us apart. So this will be a story of one family — but our story, I hope, will resonate and inspire."