Cardier was born in
Orléans, France, in 1956. She has worked as a journalist, and began to write children's literature in 1995.
My Parents are Getting Divorced with
Melissa Daly was published in English in 2004 by
Amulet Books as part of the
Sunscreen self-help series aimed at teenagers. A review in the
School Library Journal described it as "a great, upbeat book, giving wise advice in a voice that speaks to kids", although said it was unfortunate that "all but one of the titles in the bibliography are in French".
Booklist praised it for its "conversational and warm" tone and "solid, reassuring advice". Cadier's 2009 novel
Le Rêve de Sam received the 5th/4th level prize of the
Dévoreurs de livres award, elected by students and teachers in
Eure. It also received the Literary Al Terre Ado prize at the Hermillon Book Fair, and the
Prix Ados en colère at the 2010 (a book fair held in
Arras). In 2011 Cadier received the
Randell Cottage Writers' Residency and spent six months in
Wellington, New Zealand. Her 2015 collection of short stories,
Contre courant, focuses on the theme of civil disobedience from a humanist perspective. Her 2023 novel
Né coupable was about the trial of
George Stinney and was supported by
Amnesty International. It received the 5th/4th prize at the awards, elected by young readers, and the
Prix littéraire des jeunes Caladois awarded by young people of
Villefranche-sur-Saône. ==Selected works==