Bello moved to Philadelphia in 1962 where she participated in LGBT social and political organizing. These nascent actions became known as the homophile movement. In 1967, Bello became a founding member of the Philadelphia Chapter of the Daughters of Bilitis (DOB). Bello edited the DOB-Philadelphia newsletter with fellow activist Carole Friedman. They both influenced the decision to dissolve DOB and create the Homophile Action League (HAL) in 1968. Bello worked as the editor of the HAL newsletter which challenged police harassment against the LGBT community. In 1968, Bello decided to become an activist after the Philadelphia Police Department raided Rusty's bar and arrested 12 women. HAL requested meeting with the police department. Due to her immigration status, Bello did not participate directly in the meetings, but drove the car. Bello attended the final Annual Reminder day protest in 1969, having received U.S. citizenship that year. Bello's advocacy efforts in the late 1960s and early 1970s served as a "bridge between pre- and post- stonewall political activities."