Siren does not make a good name. If you leave aside the deadly mermaid angle, there's the loud fire/police/ambulance alarm sound, which is what usually springs to mind first anyhow. Even for a mermaid name, it's as painfully obvious as a whack across the head with a two-by-four.
You're entitled to your own opinions. You're not entitled to your own facts. -- Daniel Patrick Moynihan