The Guatemalan woman credited with inventing the McDonald’s Happy Meal has died, Newsweek reports. Yolanda Fernández de Cofiño, 87, died Monday, only three years after she left the McDonald’s franchise she had owned since 1974. McDonald’s Guatemala noted her passing in a statement on Twitter. “McDonald’s Guatemala deeply regrets the sensitive death of its president, Mrs. Yolanda Fernández de Cofiño,” the company wrote, per Newsweek. “This is, without a doubt, one of the most difficult and sad moments for the family, the company and its thousands of collaborators in Guatemala.”

Fernández de Cofiño launched the kids-centered “Ronald Menu” at her Guatemalan franchise in the 1970s after realizing that the meal portions were too large for children. The decision was eventually adopted by the company in the U.S., leading to the launch of the Happy Meal in 1979. Fernández de Cofiño is also credited with the first birthday parties allowed inside a McDonald’s, which led to the company awarding her a “Ronald Award.”