A Patchwork Planet by Anne Tyler
Barnaby Gailtin has less in life than he once had. His ex-wife Natalie left him and their native Baltimore several years ago, taking their baby daughter Opal with her, and he has acquired an unalterably fixed position as the black sheep of the family in a family where black sheep aren't tolerated. Then the angelic Sophia enters his life and it seems as if all this is set to change.