Just keep swimming

Emily Jones. She had everything, or so she thought. When her 'best friend' tells everyone her secret. Her world comes crashing down. She left but now she's back. Nothing's okay, she isn't okay. Then one night, an old lady hands her a crystal 'Wear this, it'll grant you the wish you made on your ninth birthday'. She had wished to be a mermaid. She took it, not believing her at all. Little did she know, everything was about to change. Along the way she meets Kieran, and Mabel. Are they her friends, or her enemies?