Daughter hallucinating

Has anyone had this experience I need help on what to do. My step daughter who is 13 has recently been saying voices have been bothering her. They call her names and say negative things to her. It really makes her upset. Idk what to do. She spends most of the time on her phone besides doing activities with her dad. I work and mostly stay in my room. She’s homeschooled. Also her mother dropped her off with us indefinitely. She’s only seen her once in a year. I’m not sure if this is happening because of isolation.