Cooper began her career as a children's librarian at the
Winnetka Public Library. She has also written numerous children's books about feminism and politics. In the mid-2000s,
John Green was working at
Booklist, where he was mentored by Cooper, when his book
Looking for Alaska won the
Michael L. Printz Award. During this time, Green gave a draft copy of
Looking for Alaska to Cooper, before the book was published; Cooper later recalled that after reading this draft, she thought that "He had a voice you could tell was quite original," and decided she would work with him. She has also described herself as Green's "fairy godmother". In 2002–2003, Cooper won a
National Jewish Book Award in the Children Literature category for
Jewish Holidays All Year Round. In 2007, she won the
Illinois Reading Council Prairie State Award for Excellence in Writing for Children. ==References==