Early in her career van Keulen made drawings, stories and poems for the magazine
Propria Cures. Van Keulen made her debut in 1972 with the book
Bleekers zomer. In 1991, she won the
Nienke van Hichtum-prijs for her children's book
Vrienden van de maan. In 2021, she won the J.M.A. Biesheuvelprijs for her short stories collection
Ik moet u echt iets zeggen. Van Keulen's children's books have been illustrated by various illustrators, including
Thé Tjong-Khing, Willem van Malsen and
Jan Jutte. Some of van Keulen's work has been published under the pseudonyms Josien Meloen and Constant P. Cavalry. == Politics ==