In one work, a lizard appears near the form of a disembodied human hand. In another, a monkey with a perfectly curled tail stands amid fruit. Both seem poised to move.
"I want my animals to feel alive," Ms. Stewart told a biographer for the Smithsonian.
Her renderings were based on studies of animals in books, said her husband, Matthew C. Gruskin.
"She was very intuitive. She would start a piece and know where it was going. It wasn't planned out," he said.
Ms. Stewart graduated in 1971 from Moore College of Art with a bachelor's degree in fine arts.
Her works caught on quickly and have been shown at the Philadelphia Museum of Art; the American Craft Museum in New York; the International Ceramics Exhibition, Hovikodden Art Center, Museum of Modern Art in Oslo, Norway; and the Renwick Gallery of the Smithsonian American Art Museum.
One of her pieces is in the Hermitage Museum in St. Petersburg, Russia, where she was recently invited to speak. She declined because of health reasons.
Among the grants she received were an artist's fellowship from the National Endowment for the Arts, and an individual fellowship from the Pennsylvania Council on the Arts.
Her work has been described in reviews as "stunning," "breathtaking," and "brilliant," as well as "disconcerting," the latter because of the juxtaposition of elements. What, for example, is the lizard doing near the human hand in one sculpture? Will it bite? The work raises questions, inviting the viewer to supply a narrative.
"It's almost like you're waiting for the next frame," her husband said.
Gallery owner Helen Drutt, with whom she maintained a close personal and professional friendship, described Ms. Stewart as a study in contradiction.
"She wasn't an assertive person. She just made amazing art," Drutt said.
Ms. Stewart was born in Philadelphia and grew up in Southampton, Bucks County, where she graduated from William Tennent High School. She and her husband met on vacation in the U.S. Virgin Islands and married in 1990.
"She was very big in the professional world, but around here it was 'Mom' and 'Liz,' and 'Take out the trash' and 'Clean your room,' " her husband said.
Surviving, besides her husband, are a son, Matthew B., and a nephew.
A memorial and burial are private.
Contact Bonnie L. Cook at 610-313-8102 or firstname.lastname@example.org.