Geraldine Hoff Doyle, who was believed to be the unwitting model for the “We Can Do It!” poster of a woman flexing her biceps in a factory during World War II  an image that later became a symbol for the American feminist movement  died on Sunday in Lansing, Mich. She was 86.

The cause was complications of arthritis, said her daughter Stephanie Gregg.

Mrs. Doyle was unaware of the poster’s existence until 1982, when, while thumbing through a magazine, she saw a photograph of it and recognized herself. Her daughter said that the face on the poster was her mother’s, but that the muscles were not.

“She didn’t have big, muscular arms,” Mrs. Gregg said. “She was 5-foot-10 and very slender. She was a glamour girl. The arched eyebrows, the beautiful lips, the shape of the face  that’s her.”