Soupy Leaves Home — Cecil Castellucci

Pearl "Soupy" Plankette ran away from her abusive father, but has nowhere to go until she stumbles upon a disguise that gives her the key to a new identity. Reborn as a boy named Soupy, she hitches her star to Remy "Ramshackle" Smith, a hobo who takes her under his wing. Ramshackle's kindness and protection go a long way to help Soupy heal from her difficult past. But Ramshackle has his own demons to wrestle with, and he'll need Soupy just as much as she needs him.

Set in 1932, this is the story of two misfits with no place to call home, who build a relationship during a train hopping journey from the cold heartbreak of their eastern homes toward the sunny promise of California.