The female Administrator was the second Administrator seen in the series. In the third book it is revealed that she is actually working for the Diablerie, and nearly manages to kill both Mr. Bliss and Valkyrie Cain.
Playing With Fire
The Administrator makes a small appearance escorting Valkyrie and Skulduggery.
The Faceless Ones
The Administrator is revelealed to be the spy working in the Irish Sanctuary. She manages to trap Mr. Bliss in symbols that would take his energy and kill him. She manages to stop Valkyrie and nearly kills her as well, until the Cleavers arrive. The Adminsitrator is pushed into the symbols, freeing Mr. Bliss, and she dies.