She lived most of her childhood in Long Island. She enjoyed horseback riding, and became a babysitter to help raise funds for her rides. Her interest in art was recognized and nurtured by her parents. Her teachers also encouraged her by allowing her to design and paint the sets of plays.
After many disappointing jobs, she decided to attend Cooper Union for the Advancement of Science and Art. After graduation, she began work in graphic design, and married fellow artist Donald Crews. After her husband was drafted into the army in 1963, they moved to Frankfurt, Germany. Their first daughter, Nina Crews was born in Germany, and their second, Amy, was born a year later in New York.
When they returned to the United States, Jonas continued her work in graphic art, while her husband began to focus on illustrating children's books. Many years later, when their daughters were almost ready for college, Jonas wrote and illustrated her first children's book When You Were a Baby, in 1982, although it wouldn't be published for another nine years. Her 1983 book Round Trip was recognized as an ALA Notable Book and a New York Times "Best Illustrated Book".
- Two Bear Cubs (1982)
- Round Trip (1983)
- Holes and Peeks (1984)
- The Quilt (1984), ISBN 978-0688038250
- The Trek (1985)
- Where Can It Be? (1986)
- Now Can We Go? (1986)
- Reflections (1987)
- Color Dance (1989)
- When You Were a Baby (1991)
- The 13th Clue (1992)
- Aardvarks, Disembark (1994)
- Splash! (1995), ISBN 9780688152840
- Watch William Walk (1997)
- Bird Talk (1998)
- Stars Beneath Your Bed: The Surprising Story of Dust (April Pulley Sayre, 2005), ISBN 9780060571887
- Ann Jonas, National Center for Children's Illustrated Literature
- Betty Debnam, Meet Author/Illustrator Ann Jonas, The Mini Page, October 13, 1998
- "Author Ann Jonas Dies, New CLA “Briefings” Posted". Bay Views. Retrieved 25 September 2014.