An at-least-similar good book about mermaids is "Mermaid Tales from around the World" by Mary Pope Osborne, a beloved contemporary author of dozens of well-researched and well-written books for children of all ages. The cover art features a mermaid with a green tail, and she does have sparklies in her hair. There are tales (no pun intended) of mermaids in China, Iran, and Africa, etc.
If it's your book, you might also enjoy reading some of Mary's many other good books, e.g. "Tales from the Odyssey," "American Tall Tales," "Favorite Medieval Tales," "Run, Run, as Fast as You Can," and of course the Merlin Mission series.