The Case of the Questionable Cousin

In "The Case of the Questionable Cousin" by Vicki Berger Erwin, middle school student Elizabeth uses knowledge from her science fair project on blood types to investigate a mysterious young woman who claims to be her Aunt Nan's niece. The story takes place in a contemporary setting where Elizabeth becomes suspicious of the woman's true identity. As Elizabeth applies her scientific knowledge to the mystery, she works to uncover whether the newcomer is truly related to her family or has ulterior motives.