Kathleen Thompson Norris was born in San Francisco, California on July 16, 1880. Her parents were Josephine (née Moroney) and James Alden Thompson. When she was 19 both her parents died. As the oldest sibling she became effectively the head of a large family and had to work. Initially, she found employment in a department store, which was soon followed by work in an accounting office and then the Mechanic's Institute Library. In 1905, she enrolled in a creative writing program at the University of California, Berkeley and began writing short stories. The "San Francisco Call", which had published a few of her stories, hired her to write a society column in September 1906. In the course of that work she met Charles Gilman Norris (whose late older brother was the famous novelist Frank Norris), and they soon fell in love. He moved to New York to be art editor of "The American Magazine". After eight months of daily correspondence and some improvements in her family's financial situation, she joined him there and they were married in April 1909.