[3] The Countess developed an interest in a wide range of subjects, including regionalism through Touraine folklore, and became a committed suffragist.

From the 1890s onwards, Countess Lecointre built up a large collection of Miocene fossils and conducted studies on the Touraine cliffs, initially on her own.

She then relied on regular exchanges with other European scientists, notably Gustave-Frédéric Dollfus (1850–1931), President of the French Geological Society, who had a major influence on her; Philippe Dautzenberg (1849–1935), a Belgian malacologist and zoologist; Lucien Mayet (1874–1949), a lecturer at the University of Lyon; and Constant Houlbert (1857–1945), a professor at the University of Rennes and an entomologist.

Her book Les faluns de Touraine (Tours, 1908) reviews the fossil record and the evolution of ideas on the subject throughout history.

The same year, she compared the faunas of the Touraine deposits with those of the Middle Miocene collected in the southeastern United States.

In 1884, she helped found a nursing society, and in 1908, the National Civil Rights and Women's Suffrage Congress.

Her son paleontologist Georges Lecointre continued her work, demonstrating the value of falun as an agricultural soil improver.