The Black Pearl — Louise Cooper

Since her family moved to Cornwall, Lizzy's world has been turned upside down by the discovery that she has a long-lost brother, Kes, and even more amazingly that their mother is a mermaid. Now Lizzy and her new family must bravely battle the evil sea queen and her terrfying servant, for Lizzy has a powerful treasure and the sea queen will stop at nothing to get it.

Exciting and full of dark mystery and suspense, ideal for girls of 8â€"10 who love stories with an edge.