Who is Chloe from Wondrous Strange and what is their importance?

Chloe is a siren that now lives in the mortal world. She learns Kelley's true identity when she steals a song from Kelley while she is helping the horse out of the lake. When Mabh finds out that Chloe revealed Kelley's identity to Auberon, Mabh feels Kelley is in danger. She then tortures Chloe and eventually kills her.