Dancing Shoes by Noel Streatfeild (aka Wintle's Wonders)

Title: Dancing Shoes
Author: Noel Streatfeild
Illustrator: Richard Floethe
Publication: Yearling paperback, 1980 (originally published in 1957)
Genre: Juvenile fiction
Setting: 20th century London

Description: As Rachel and Hilary’s mother is dying, she urges Rachel to make sure talented Hilary continues with her ballet. Once orphaned, the ten-year-olds are given a home by Rachel’s father’s brother Tom and his wife, Cora. Cora runs a theatrical school, Wintle’s Wonders, and does not initially plan to give a home to Hilary, "only" an adopted niece, until she sees Hilary dance and recognizes she has potential – although she does not think Hilary is as gifted as her own daughter, Dulcie, destined for stardom.