Mrs. Lasswell died of respiratory failure at her daughter’s Beverly Hills home, family spokesman Lonnie Soury said.
Mrs. Lasswell, born Shirley Ann Basso on May 27, 1923, was married to the late Stephen Slesinger, who in 1930 obtained U.S. and Canadian licensing and merchandising rights to Pooh, Christopher Robin and other characters created by British author A.A. Milne.
When her husband died in 1953, she took over development of the characters and creating clothing, dolls and other items.
She licensed Pooh to Disney in 1961, the first of two licensing agreements between Stephen Slesinger Inc. and the Walt Disney Co.
Stephen Slesinger Inc. sued Disney in 1991, claiming the company miscalculated royalties due under that deal. Disney denies additional royalties are owed.
A dismissal of Mrs. Slesinger’s main lawsuit is being appealed in state court.
In 1964, she married Fred Lasswell, the cartoonist behind “Snuffy Smith” and “Barney Google.” He died in 2001.