Flannery finished her PhD in music composition and musicology at the University of Pennsylvania and works as Promotion Manager with the music publisher G. Schirmer, where she works to increase programming of contemporary music by orchestras, dance companies, and other ensembles. She continues her own work as a composer and researcher, including  premieres of works for PRISM Quartet and Carnegie Hall's "Link Up" program and a paper at the 2023 International Medieval Congress. In January 2021, she was named by the Washington Post as "21 for '21: Composers and performers who sound like tomorrow." She is fascinated by illusion and auditory perception, music as a driver of drama, and the performative possibilities of interactive electronics. She was commissioned by Sopraltus of the MacPhail Institute, the Minnesota Center Chorale, the Cornell University Chorus, and the College of St. Benedict/St. John’s University. She has written dramatic works including an oratorio about the 6th-century Irish monk St. Brendan the Navigator and a (pre-Hamilton) opera about the Burr-Hamilton duel. An active poet, Flannery often writes her own texts and libretti. In addition to acoustic ensembles she writes for live players with realtime electronics, always striving to create an environment that foregrounds the skills and musical voice of the performer. She holds an MA in Composition from University College Cork as a Mitchell Scholar and an MA from Stony Brook University. Flannery obtained her undergraduate degree from Princeton.