The Little Mermaid: The Adventures of Melody

Introduction

It all stars where it left off. King Triton froze Morgana on ice, who swept in the Arctic waters. Then Melody with Triton's trient, she removed the great wall around Tirulia Castle, that closed her off to the sea. Then King Triton with his trident did a magic in the sea, that makes a mermaid/merman go ashore to become a human. And when she/he go back to the sea, she/he turns back into a mermaid/merman. So Melody went to Atlantica many times and got to know her cousins:

Aaron and Aaliyah (twins of Attina)
Alan (son of Adella and Stevie)
Arabella (daughter of Andrina)
Aquaria (daughter of Aquata)
Ares (son of Arista)
Ellie (daughter of Alana)

Melody even learned about her monther's family background. She learned how her grandmother, Queen Athena had died, that Triton had banned music in Atlantica for 10 years, and what adventures her mother, Ariel had.

But before all of that, before of Melody's 10th birthday, Ariel became pregnant again, and Melody's birthday, a few weeks later, Melody's little sister, Ariel and Eric's second daughter, Harmony was born. When Melody find out of her maternal parentage and met Morgana, Harmony was 2-years old.

By the time Harmony was 3 years old, Ariel and Melody were already able to take her to Atlantica. Because Harmony is a half-human half-mermaid, just like Melody.