She died of atherosclerosis, a condition where fatty deposits collect on the walls of blood vessels. Although more prevalent in older adults, it can affect those of any age.
Last name is pronounced "Shay."
Her father was Chinese-born and her mother was an American with Scotch-Irish ancestry.
In the 1960's, Hsueh had a pet dog who was part coyote. It was given to her by a native American in Moab, Utah, while on the set of Cheyenne Autumn (1964).