Fallon has been married to love of her life Paeter Hogan since a long time. Paeter Hogan is a commodities trader. As a married couple they have been parents three times.
After earning her high school graduation from some high school in United States, Fallon got enrolled at Le Moyne College. She also graduated from there in 1983. Then she got enrolled at Catholic University of America. She has been active in acting since 1990; however, she made her acting debut in 1981 and that was in the TV show, The Unnaturals. In 1990, she appeared in the TV series, The Golden Girls where she starred the role of Abby Wolfe. The following year, she appeared in the TV series Baby Talk, Babes, Seinfeld and so on. Her breakthrough role came in 1997 when she starred the role of Beatrice in the movie, Men in Black.