Hermione Hendricks was one of thirteen children born to Frances Isaacs and Harmon Hendricks, metallurgist, entrepreneur, and early industrialist. When, in 1847, Hermione married Isaac Alfred Tobias, the couple further linked the Tobias and Hendricks families, already connected through three previous marriages: Fanny Tobias and Uriah Hendricks, Harriet Tobias and Henry Hendricks, Henry Tobias and Roselane Hendricks. Hermione and Isaac lived in New York and had five children.