Enchanted Shell (The Secret Mermaid #1)2009
by Sue Mongredien
When Molly Holmes moves with her family to Horseshoe Bay, her grandmother gives her an enchanted shell necklace that magically transforms her life. The power of the necklace transports Molly to the Undersea Kingdom, where she discovers that she is a secret mermaid and meets lots of new mermaid friends.
— from OpenLibrary
1 edition at OpenLibrary