Ms. Claus's List

I am Ms. Claus.
Note the Ms. not the Mrs.?
Santa is my twin brother—not sure how the married rumor got started, eeew!—but he runs the North Pole except for that one most magical night of the year: Christmas Eve. When Santa is away, the elves will play. With me, if they’re lucky enough to be picked from my List.
Please, no nice elves need apply. Because I really want to find out how naughty you can be!