Margaret Valentine was the former Secretary of Agriculture and current President of the United States. She becomes President after the other ranking woman on the chain of succession, Secretary of the Interior Richburg, dies in a plane crash (at the time the comic was written, the real Secretary of Agriculture was Ann Margaret Veneman, and the real Secretary of the Interior was the highest woman in the Cabinet). She evidently won a term of her own right in 2004, although she recognizes it is because she is the most famous woman as "no one knows where Oprah is hiding."
She had a "worthless" ex-husband who died in the Plague.