Books like The mermaid's tail by Raewyn Caisley

Merliah, a Barbie character, discovers she's a mermaid princess and embarks on a journey to save her mother from evil.

Barbie has an adventure as a mermaid.

A young girl discovers a secret about herself that leads her to a new world of swimming and mermaids.

Best friends meet the sea, but the school's snobbery ruins everything as Shelly and Echo face a new challenge: schoolwork.

Three tales of Disney princesses: Ariel, Tiana, and Rapunzel.

Electra, the nine-year old mermaid with legs instead of a tail is back and in search of even more adventure! It's New Year on Mermaid Island. Every year a young Queen of the New Year is chosen and Electra is desperate for it to be her! So she might get chosen, Electra and her dolphin friend, Splash, decide to swim over to the grotto to help the grown-ups decorate it for the New Party. But Electra and Splash get carried away and make a BIG mess in the grotto. Sent away to behave, the two of them discover tunnels at the back of the grotto which lead to the deep sea. All the tunnels are safely blocked up except one. Electra and Splash try and tell the adults but they are too busy fixing the mess to listen! So when a group of sharks swim down the tunnel and threaten to eat everybody it's up to Electra and Splash (and a giant ink squirting squid) to save the day!

An adventure for Electra and her friends on Craggy Island, where mermaids are mean and the caves are haunted.

Three-year-old Aluna and her friend Hoku go to the forbidden Undersea Colony to find help when their underwater devices start failing.