Yvonne Shepard Cosby, 93, a novelist and short story writer who was active on behalf of animal welfare, died of an aneurysm Tuesday at her Washington home.

Mrs. Cosby, who was born in Paris, France, moved here with her family in her teens. She was educated in this country and abroad.

In 1909, she married Army Col. Spencer Cosby, district engineer commissioner and military aide to president William Howard Taft. Col. Cosby supervised the acquisition and planting of the first Japanese cherry trees here in 1912 and served that same year as secretary of the Lincoln Memorial Committee. He died in 1962.

Mrs. Cosby and her husband made their home here after his military retirement in 1928.

In the 1920s and 1930s, Mrs. Cosby wrote two novels and a number of short stories. The novels, "Gentleman of Sorts" and "Custody Children," published in this country and in Europe, as well as the short stories, were written under the pen name of Everett Young.

Mrs. Cosby was a former president of the Washington Animal Rescue League and a founding member in 1954 of Welfare of Animals Used for Reserach in Drugs and Surgery (WARDS), a national organization based here. She served as chairman of WARDS for several years.

She was a member of the Sulgrave Club and St. Thomas' Parish Episcopal Church here.

There are no immediate survivors.