It's not surprising this is such a classic story. I first read it when I was around nine, and was captivated by all three protagonists. Pauline, Petrova and Posy Fossil are all adopted as babies by Great Uncle Matthew (known as Gum) and sent to live at his house in London, along with his massive collection of fossils. They are looked after by the thoughtful Sylvia and the practical Nana.
The story really begins when the money Gum has sent for the girls' upbringing runs out. Sylvia and Nana don't know how to contact him; they have no idea where he is; there is even some suspicion he may be dead. Then one of the people who boards with them comes up with an idea for the three girls to attend a school of Dance and Acting so that they can earn some money through stage productions. In different ways, their training at the school is the making of all three girls.
Streatfield is careful to make the girls' characters as distinctive as their looks: tall, blonde and beautiful Pauline is interested in English and Drama; Petrova, who is thin and dark, is of a practical frame of mind, good at Maths and Mechanics; while Posy, to whom the shoes of the title belong, has a talent for showing off. The book is truthful about the way sisters interact, their squabbles, the way two band together against one (often it is Pauline and Petrova against Posy, as they try to stop her showing off), how fame can affect young children. There is often a great deal of scrimping and saving, but the girls never let this depress them. As the book draws to a close, Pauline's and Posy's futures become clear, but Petrova's remains uncertain. You wonder what will happen to her; you wonder if Gum will ever appear again.
A great book for all little girls, not just those interested in ballet.