The youngest of seventeen children, Phelps grew up in a household that encouraged reading and intellectual discussion in all its children. At the age of sixteen, while staying at the home of her older sister (Emma Willard, an activist for improvements in female education), Phelps gained a clearer understanding of the imbalance in educational opportunities for men and women. As a result, much of her own educational career was dedicated to improving academic choices for girls and young women. For much of her life she travelled giving teaching lectures and headed multiple female educational institutions. While teaching at the Troy Female Seminary in New York, Phelps’s interest in botany grew through a friendship with botanist and educator Amos Eaton. She gained a great passion for the subject and, recognizing the lack of helpful textbooks on the subject for secondary and early college students, wrote her most well-known textbook, Familiar Lectures on Botany. Published in 1829, it drew on writings from botanists such as Mirbel, Woodville, and Torrey. The unqiue arrangement of scienfitic and physical information about each plant and flower and its numerous clear illustrations helped the book become a success, and it went through nine editions over the next ten years. Its was especially popular amongst female students in schools and seminaries, and Phelps and her books can be said to have a major hand in the spread of botany as a hobby or scholarly interest for women of the 19th century.