Madame Giry
The choreographer of the corps de ballet in the Opera Garnier. She is the mother of Meg, and has a history with the Opera Ghost.
Where is she from?
Giry is a character in Gaston Leroux's 1909 novel The Phantom of the Opera, where she is essentially the Phantom's servant and representative. Her role within the story shifted quite a bit in the various representations of the story, often being removed completely... so the massive character shift in the GND Universe isn't actually that far-fetched.
In the Andrew Lloyd Webber Musical, Giry is combined with another character from the novel, the Persian, in that she now also leads Raoul into the Phantom's catacombs. In the 2004 Joel Schumacher movie, where she was played by Miranda Richardson.