Mann worked as a staff photographer at Washington and Lee University. In the mid 1970’s she photographed the construction of their new Lewis Law Library, leading to her first one-woman exhibition in late 1977 at the Corcoran Gallery of Art in Washington, D.C. Those surrealistic images were then included as part of her first book, Second Sight, published in 1984.
Her second collection, At Twelve: Portraits of Young Women, published in 1988, stimulated controversy. The images captured the confusing emotions and developing identities of adolescent girls [and the] expressive printing style lent a dramatic and brooding mood to all of her images.
Mann is perhaps best known for Immediate Family, her third collection, published in 1992. The NY Times said, “Probably no photographer in history has enjoyed such a burst of success in the art world.” The book consists of 65 black and white photographs of her three children, all under the age of 10. Many of the pictures were taken at the family's remote summer cabin along the river, where the children played and swam in the nude. Many explore typical childhood themes (skinny dipping, reading the funnies, dressing up, vamping, napping, playing board games) but others touch on darker themes such as insecurity, loneliness, injury, sexuality and death. The controversy on its release was intense, including accusations of child pornography (both her and abroad) and of contrived fiction with constructed tableaux. One image of her 4 year old daughter (Virginia at 4) was censored by the Wall Street Journal with black bars over her eyes, nipples and vagina. Mann herself considered these photographs to be “natural through the eyes of a mother, since she has seen her children in every state: happy, sad, playful, sick, bloodied, angry and even naked.” Critics agreed, saying her “vision in large measure is accurate, and a welcome corrective to familiar notions of youth as a time of unalloyed sweetness and innocence,” and that the book “created a place that looked like Eden, then cast upon it the subdued and shifting light of nostalgia, sexuality and death."