Barbara Grace de Riemer Sleigh (1906-1982) was an English children's writer and broadcaster. She worked for the BBC Children's Hour and is the author of Carbonel and two sequels: The Kingdom of Carbonel and Carbonel and Calidor.
A most entertaining story, I'd say for eight to tens, about a girl, a boy, a snowman, a snow-woman, and a snowball with a difference. The black-and-white illustrations by Patricia Drew bring out the story well. What I also liked was the conversational English, bringing a plain but expressive vocabulary. So I think this is a good one for younger learners of English too. Published in 1969. It's out of print, but fairly easy to obtain second-hand.