In 1887 Hillis helped found the Des Moines Women's Club, and she raised money for the organization by giving lectures on the fine arts in her home. Hillis first ventured into advocacy work in 1894 when she campaigned to create a safe public swimming facility for children in the
Des Moines River, including a bath house and rental swimwear for those who could not afford their own. After the death of her son Philip in 1893, Hillis became involved in the "mother's congress" movement (later became the
Parent-Teacher Association) that promoted an educated approach to parenthood and child-rearing. She attended the 1899 National Mothers' Congress in Washington, D.C., serving as a delegate from the Iowa Child Study Society. Hillis became highly involved in the organization. She organized the next Congress, which took place in
Des Moines in May 1900, and she was elected the first president of the Iowa Congress of Mothers. The organization advocated for recognizing the responsibility and commitment of parenthood, and for discarding inaccurate gender stereotypes. In 1914, after taking the idea to the four previous presidents of the University,
Thomas Macbride agreed to support and move forward with the idea. Together with
Carl Seashore, Dean of the Graduate College, Hillis campaigned the state legislature to allocate funds to establish such a center. Finally, in April 1917, the Child's Welfare Bill was signed into law in Iowa. It established the
Iowa Child Welfare Research Station (now the Institute of Child Behavior and Development), which researches children's physical growth, intellectual development, speech development, and aspects of teacher training. ==Personal life==