This book is about a girl named Bobby Lassiter, who has just turned 10 as we meet her. She is living in the California desert with her mother and her 20 year old sister. The depression is just around the corner, but this family knows poverty just fine -- they barely scrape by on the proceeds of the older women's knitting. The father, who was evidently terribly abusive (physically -- whippings of all three -- not sexually) left them when Bobby was very young. Bobby (full name Roberta) is apparently called Bobby because the father wanted a boy -- and, indeed, no one but her sister and mother knows she's a girl.
She meets a man on their property one night, who tells her he is really a horse, named Mister Boots. He too has been abused by his human owners. Bobby feeds and clothes him, and eventually takes him home. Events follow quickly from their. The mother dies. Mister Boots and the older girl, Jocelyn, fall in love. Their father, Robert Lassiter, returns and the abuse begins again. He wants Bobby to become a magician, just like him -- and she finds she is good at that, and wants to do it. They head to LA (Bobby dressed as a boy -- which her father still thinks she is), and become a successful magic act, despite Mister Boots's refusal to turn into a horse onstage. Bobby makes her first ever friendship with a girl her age: a similarly bereft Mexican girl named Rosie whom she meets in a sort of hobo camp. They meet their father's long time mistress -- or is she really his wife, and are they illegitimate? But then the Depression hits, and the money dries up, and things get worse and worse, until a final revelation and a final horrible act.
It's a charming and hopeful story in one sense, with a delightful narrator in Bobby. (Yet a real seeming narrator -- not a prodigy, for instance, and far from a perfect person.) Yet it is also quite dark -- the depression, the abuse, and a somewhat tragic denouement. Which I think means it's really pretty much like real life. A fine little novel.