Shoddy Cove by Betty Levin

Clare's summer has been ruined. With Dad away, Clare is forced to accompany her mother to the Cossit Island Village living historical museum. Every day she has to wear long, awkward 1830s-style dresses and card wool in the hot, gloomy Grimes homestead.

Then two children appear -- a boy who knows how to spin wool without even using a spindle and his little sister who throws a fit in the middle of a funeral reenactment. They are not ordinary tourists. Clare sees them day after day.

Who are these strange children? What are they doing at Cossit Island Village? As Clare tries to unravel their story, she stumbles upon a second mystery, nearly two hundred years old, and just as intriguing and suspenseful as the first...