What is the name of Don Geiss's daughter on 30 Rock?

Kathy Geiss is the name of Don Geiss's daughter on 30 Rock.

Kathy is played by Marceline Hugot and belongs to the show's recurring General Electric storyline. Her father, Don Geiss, is the powerful GE chief executive and Jack Donaghy's mentor. Kathy is portrayed as an eccentric, unusual woman whose behavior repeatedly surprises the executives around her.

When Don falls into a coma, Kathy nominally holds the titles of GE chairman and chief executive, as well as president of East Coast Television and Microwave Oven Programming. In practice, Devon Banks uses her position for his own purposes, making her succession a satirical take on corporate power and figurehead leadership.

Viewers sometimes confuse Kathy with Avery Jessup, who is Jack's wife, or with Cerie Xerox, Liz's young assistant. Kathy is specifically Don Geiss's daughter; her brother Bertram is another recurring joke in the Geiss family mythology.