Complex sentence: May spent more than three decades as an Indianapolis educator, twenty-five of them at the Girls' Classical School, which she founded with her second husband, Theodore Lovett Sewall, in 1882.
Split into simpler sentences: May spent more than three decades as an Indianapolis educator. Twenty-five of them were spent at the Girls' Classical School, which she founded with her second husband, Theodore Lovett Sewall, in 1882.