So B. It
Sarah Weeks
 Twelve-year-old Heidi lives in the town of Reno, Nevada with her mentally-disabled mother and their neighbor, Bernadette. Her mother only knows twenty-three words, including one mysterious one, "soof," that no one can define. Meanwhile, Bernadette has a serious condition called agoraphobia, which causes her to be too afraid to go outside her house. Heidi must take on responsibilities beyond her years to provide for their households. When Heidi finds some photos of her mother at a Christmas party in New York, Heidi decides to go to that state, anxious to uncover more about her family history and to seek what the word "soof" meant, after hearing her mother mutter it all the time. Although Bernadette is anxious about Heidi leaving, she reluctantly allows her to go as long as she calls every night. During her road trip to Liberty, New York, Heidi meets Georgia Sweet, a kind and curious lady on the bus. When she arrived at Hilltop Home, she felt unwelcomed by Thurman Hill. Feeling sorrowful, Ruby takes Heidi into her own home where she and her husband, Roy, investigate. She discovers that Thurman Hill, is her grandfather, Elliot is her father, and that her grandmother was named Diana. She finally finds out what her mothers word, soof, meant, which was her nickname for Sophia Demuth. By the end her mom dies.