Cecilia Fryxell early supported herself as a governess to wealthy families: first to the landowner L. M. Uggla at Svaneholms manor in Dalsland and thereafter to landowner and courtier Olof Nordenfeldt at Björneborg in Värmland south of Kristinehamn In 1843, she decided to become a missionary after a sermon held by Peter Fjellstedt.

Instead, she studied the boarding schools for girls in Switzerland and Germany in 1843–1847, and was employed as a teacher at Waisenhaus in the Basel Institute.

In 1852, she moved her girls' school to an estate of Count G. Lewenhaupt, Carlslund outside Västerås, where she could house 100 students.

She is described as strong and forceful and not tolerant in questions of religion and personal morals, but despite this, life at her school was described as informal, familial and jolly.

Many of her students became teachers and founders of girls' schools themselves in other parts of the country, such as Elsa Borg in Gävle, Sophia Posse and Frederique Hammarstedt in Stockholm, Natalia Andersson in Västerås, Maria Henschen in Uppsala and Sigrid Rudebeck in Gothenburg.