After receiving her nursing diploma, Mahoney worked for many years as a private care nurse, earning a distinguished reputation. She worked for predominantly white, wealthy families. The majority of her work was with new mothers and newborns, and had been done in New Jersey, with the occasional travel to other states. During the early years of her employment, African American nurses were often treated as if they were household servants rather than professionals. Mahoney emphasized her preference to eating dinner alone in the kitchen, distancing herself from eating with the existing household help, to further dismiss the relation between the professions. Mahoney also lived alone in an apartment in Roxbury where she spent time reading and relaxing, while also attending church activities with her sister. Nevertheless, families who employed Mahoney praised her efficiency in her nursing profession. Mahoney's professionalism helped raise the status and standards of all nurses, especially minorities. Mahoney was also known for her skills and preparedness. As Mahoney's reputation quickly spread, she received private-duty nursing requests from patients in states in the north and south east coast.