Gerd was the wife of Alf, leader of the North Family of Mither Mages. Gerd was a powerful Lightmage with the abilities to change the color of reflected light so that she, making things nearly invisible, of hide them in the shadows, or make them glow as bright as the sun.
Gerd, or Mama as she was called by him, was Danny North's mother. Having been denied permission by then-Odin Zog for so many years to have a child with Alf out of fear of a forbidden Gatemage, only to be ousted from head-of-the-Family and have the decision reversed by Alf, the new Odin.
Gerd and Alf purposefully distanced themselves from Danny during his upbringing in the event he was a Gatemage so that they might appear impartial in a decision about his survival or usefulness to the Family. Ultimately, the contributed to Danny's mistrust of his Family and his running aw way from the compound at age thirteen.