This book is about two young sisters in England during WW2. They have a father, who lets them ride a giant rocking horse out in a shed at one point (there’s an illustration of it), but not necessarily a mother. They are forced to share their Xmas gifts with an orphaned boy their age; they choose plasticine and the boy turns out to be talented. One of the sisters learns to paint a doorknob to look gold, like the old lady artist they befriend. The book is meant for children probably between 8 and 12.
Thanks in advance for your help.