Returning to Cincinnati, she spent most of her remaining years as a patron of art, and in works of charity and philanthropy, and established the Ladies' Academy of Fine Arts. Sarah Peter became a Catholic convert at Rome in March, 1855, being instructed there by Mgr Mermillod. The foundations of the Sisters of the Good Shepherd, the Sisters of Mercy, the Little Sisters of the Poor in Cincinnati and other institutions owed much to her generosity. In 1862, she volunteered as a nurse, and went with the sisters who followed General Grant's army in the southwest after the Battle of Pittsburg Landing.