After years of living abroad, ten-year-old Rianne and her family move to Reston, Virginia, where the acquaintance of a talking possum seems to influence the luck in their lives
A super cute re-released middle grade contemporary fantasy about a family moving to a DC suburb and discovering an opossum who can control luck, known as the Impossumble. It's a bit dated (it was originally published in 1992) but still very readable.