Nerves of the Heart — Lucy Ferriss

Nine-year-old Toby Ames is a boy desperately in need of a heart transplant. His salvation comes in the form of Brooke Hunter, a young girl who died with her father in a motorcycle accident. Eight months later, Toby , his parents, Nick and Susannah, and Brooke's mother, Linsey, are left to face the demands of family, love, passion, and loss.
After the deaths of her daughter and husband, Linsey Hunter moves to Roanoke, Virginia, to begin a new life near the boy who received Brooke's heart. With a void left in her life, Linsey seeks renewal within the bonds of Nick and Susannah's family. As she grows closer to Toby, Linsey begins to see a part of her daughter brought back to life through him. At the same time, Toby struggles to make Brooke's heart at home in his body and to connect with her spirit.
But Linsey's presence touches off vulnerabilities in Nick and Susannah's marriage. As their trust breaks down, Nick seeks solace in Linsey's new-age ways, and the vexed alliances of family are strained and redefined. Nick turns away; Susannah desperately tries both to give her son freedom in the face of his medical limitations and to maintain a routine that will keep him alive.