Nixie is one of the main characters in Mako: Island of Secrets
Nixie has chocolate brown hair with pretty blue eyes. When she come in contact with water she becomes a mermaid with a copper/orangeish scaly fish tail and and a maching bra top.
None at the moment
She has the Cryokinesis/Gelidkinesis power. This is Bella's/Emma's powers in H2O: Just Add Water