Tierney was raised in a small beach town on Long Island. Originally destined to study fashion, her career path was changed while waitressing at a local restaurant. After sitting in on some jazz tunes with piano player Robert Lepley, she discovered her love of Jazz. She began studying for her Music Ed. degree at Five Towns College, while teaching privately and gigging around the island. Graduating in 2010, she took a year off to teach music in city schools, and is now earning her Masters Degree at The Manhattan School of Music under the direction of Peter Eldridge.
In December of 2010, she was featured on the Rachael Ray show with her acappella quartet "The Jingle Belles" in a segment called "The Carol off", judged by Nick Canon.
Tierney has sung with such Jazz greats as Peter Eldridge, Bucky Pizzarelli, Robert Lepley, John and Peter Coco, Bob Albanese, Peter Rogine, Scott Ballin and many more.