Little Miss Thoroughbred

Gambler 'Nails' Morgan (John Litel) grudgingly becomes the not-so-legal guardian of orphan Janet (Janet Chapman) who he believes brings him good luck.

I read some contemporary newspaper accounts of this movie and its child star, and it is seems that the studio was pushing hard for Janet Chapman to be the next Shirley Temple. Janet was cute and small for her age (and she was only five), and Shirley was getting long in the tooth at the ripe age of ten. One of Shirley's big movies when she was younger was "Little Miss Marker", also set around horse racing.