"Be Careful what you Wish for!"
Four siblings in turn-of-the century England (and a two-year-old baby called the Lamb) make the discovery of an unusual creature in a sand pit: the Psammead, or Sand Fairy. Of course no adult would believe in it's existence or its super-magical ability to grant wishes--that is, one per day, which lasts (only) until sundown. While the children's parents are on a (conveniently) extended visit to an ailing relative, the kids are left in the care of Martha and the Cook at their new home in the Kent countryside.
Since the children have no experience asking for wishes, they naturally make ridiculous ones or even worse--accidental ones. The Psammead lives up to his part of the bargain, but as in darker, adult literature, the kids come to regret each of their wishes--learning wisdom and common sense too late to benefit them at critical moments. Wealth, Beauty, Wings, a live medieval castle and Native American Indians--somehow all five wishes turn out disastrously.
Now when Lady Chittenden's stolen jewels turn up in their mother's bedroom the children are hard pressed to find a creative and truthful resolution. This is a cute but quaint tale which will amuse younger readers or those who enjoy bedtime chapter books. The author can not resist interjecting a few humorous asides and, as a Fabian, insists on slipping in her views on social reform. All things considered it is a pleasant read, set in simpler, Edwardian times.