One of her works deals with Annmarie Johansen's efforts to save her Jewish friend in Nazi-occupied Denmark.
In this author's first novel, Meg becomes jealous of her sister Molly, although the two reconcile before Molly dies of leukemia. Besides A Summer to Die, this author has written about young girls like Caroline Tate and Anastasia Krupnik.  One of her works deals with Annmarie Johansen's efforts to save her Jewish friend in Nazi-occupied Denmark. FTP, name this author of Number the Stars, who also wrote about Jonas, the "Receiver of Memory," in The Giver. 
In this author's first novel, Meg becomes jealous of her sister Molly, although the two reconcile before Molly dies of leukemia.
Lois Lowry