In her normal form she is a bit over 5 feet tall, has curly light brown hair, eggshell blue eyes, and is fairly attractive. In September 2006 she is fifteen. She's also bisexual and does not hide the fact.
Duplex can copy someone's form with a touch and maintain it for up to one hour. This includes a less potent version of their mutant powers, if any. In addition she can also assume other forms, for example non-existent persons. The exact limitations on this are unknown.