The Deadly Little Mermaid.

Some secrets are better left at the bottom of the ocean. Once she's in your house, there is no escape. When a struggling artist pulls a beautiful, unconscious woman from the freezing coastal waters, he thinks he’s performed a miracle. But as she recovers within the walls of his secluded home, a series of unsettling events leads him to a terrifying realization: her presence is no coincidence. She is inextricably linked to the same watery grave that claimed his family years ago.