E. L. Konigsburg, a children’s author and illustrator who twice received the nation’s highest award in children’s literature — she won it in 1968 for her second book, edging out the runner-up, which was her own first book — died on Friday in Falls Church, Va. She was 83.

Her death was confirmed by family members, who said she suffered a stroke last week and had been hospitalized since.

Mrs. Konigsburg was the only author to have won the American Library Association’s John Newbery Medal for distinguished children’s literature, considered the most prestigious in the field, and been the runner-up in the same year.

She received the 1968 medal for “From the Mixed-Up Files of Mrs. Basil E. Frankweiler,” a story about a sister and brother from the suburbs who run away from home and surreptitiously camp out at the Metropolitan Museum of Art in Manhattan. She wrote that book in 1967, the same year she finished and sold her first book, “Jennifer, Hecate, Macbeth, William McKinley, and Me, Elizabeth,” about a new child in the neighborhood and her friendship with a girl who claims to be a witch, the 1968 Newbery runner-up.