Elizabeth is the mermaid from 2018 movie The Little Mermaid portrayed by Poppy Drayton.
Elizabeth was tricked on giving up her soul so she could find love on the dry land. Mr. Locke, as the sorcerer became known, however locked up her soul and bonded her with him, so she'd have to follow him where ever he went. Mr. Locke used Elizabeth as a circus attraction, and used the water she swam in to profit, as the water contained trace amounts of magic it healed, but only for a short time.
Elizabeth met Elle and her uncle Cameron, when they came to the circus, to write a story about the magic water, and hopefully find a cure for Elle.
While taking a walk in the forest, Elizabeth once again met Cam and Elle. When Elle asked how she can walk, she told that mermaids can have legs during the low-tide. During their conversation, she was summoned back by Mr. Locke. Back at the circus Elizabeth stopped the trainer from beating the beastman Ulysses. Elizabeth sang from sadness about being so far away from her family, and hoping to get back to them, when she heard something and saw Cameron, they were interrupted by Locke, and cam was threatened to leave.
One night, when Elizabeth again took advantage of the low-tide and walked around she went to a ferry, where she once again saw Cameron writing something, she lured him away from the book, so she'd get to take a peek in it. They started talking and found they have feelings for one-another. When the ferry stopped, Cam suggested they wait for high-tide to get moving again, Elizabeth freaked and ran away. She jumped in the water and swam. Cameron however followed her, and saw her as a mermaid. Now believing, he wanted to help her, but Elizabeth was again summoned by Mr. Locke.
Mr. Locke locked Elizabeth up, and planned on draining her of her magic, after the last show, which would kill her. Locke had also kidnapped Elle, as a vessel for the magic, which would turn her into mermaid. Cameron however stopped Locke's plans when he teamed up with the fortuneteller and Ulysses and saved Elizabeth from the tank. Fortuneteller gave Elizabeth temporary legs, and they escaped by train, planning on reaching the ocean. The train was stopped and they had to take a truck nearby. On the truck the magic expired and Elizabeth became a mermaid again. Once the truck got stuck, Cameron carried Elizabeth. They reached a cliff's edge near water, when they were stopped by Mr. Locke. Elizabeth offered her soul to fortuneteller to boost her magic, but when that was not enough Elle, took their hands and her belief enhanced it even more, stopping Mr. Locke for good. Cameron then took Elizabeth into the water, and placed the vial containing her soul onto her, healing her. Elizabeth then helped Elle to heal, and told her to swim whenever she felt sick. Elizabeth then returned her ocean home.