Audrey Geisel, widow of children’s author Dr. Seuss and overseer of his massive literary estate, has died. Random House Children’s Books announced that she died Wednesday at her home in La Jolla, California. She was 97.

Geisel founded Dr. Seuss Enterprises following her husband’s death in 1991, which was set up to license the use of the Seuss characters. Along with her involvement in numerous publishing projects and the Broadway show Seussical, she served as executive producer for some film adaptations of his work, most recently Dr. Seuss’ The Grinch, which has grossed nearly $379 million worldwide since its release last month.

Geisel also was credited with encouraging her husband to address more social issues in his books, such as The Lorax, which has environmental themes, and anti-war story The Butter Battle Book. Not one to shy away from sharing her opinions on anything involving her husband’s work, she was involved in decision-making on several Seuss commercial projects. During production of the animated film Horton Hears a Who! 10 years ago, she reportedly prompted some changes after stating she believed Horton’s teeth were too big, and the kangaroo’s pouch hung too low.

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Known for her philanthropy, Geisel was a major donor to institutions her husband supported, including UC San Diego, where she donated more than 4,000 items — original drawings and manuscripts, college notebooks, letters — to the university library, as well as the San Diego Zoo.

Geisel shared in a Primetime Emmy nomination for outstanding animated program for Daisy-Head Mayzie in 1995. The program also won a CableACE award that year for best children’s special or series.

ICM Partners, which reps Dr. Seuss Enterprises, released a statement on her passing. It follows below.

“We are deeply saddened by the loss of Audrey Geisel. Audrey lived a life of extraordinary philanthropy and was the artistic and entrepreneurial force behind Dr Seuss Enterprises. Her creativity and devotion to her husband’s work are indelibly linked with his legacy. We will miss her passion and spirit, but take solace in knowing that through her tireless devotion, every generation of children discovers their love for Things 1 and 2, The Grinch and The Lorax and will discover the endless possibilities of life’s journey through Oh The places you’ll go.”