In high school, she performed with a group called the Freedom Folk, which toured the South and performed at the White House bicentennial celebration. While attending Abilene Christian University, she sang with the school's Hilltop Singers touring choir, and also co-wrote a song with her brother called "Out of Sight, Not Out of Mind." It was recorded by Cristy Lane, which convinced Dunn to try her luck in Nashville after graduation.

While in Nashville, Dunn worked as a demo singer for a time before joining her brother as a staff songwriter at CBS. In 1984, she moved over to MTM and penned material for several different singers, including Louise Mandrell, who made "I'm Not Through Loving You Yet" a Top Ten hit. In the wake of its success, Dunn landed a record contract in her own right, and released her first single in 1985. Her self-titled debut album appeared the following year and produced her first Top Ten hit, "Daddy's Hands." Arriving in 1987, Cornerstone contained two Top Five singles in "Love Someone Like Me" and "Only When I Love," and Dunn produced its 1988 follow-up, Across the Rio Grande, herself, resulting in the hits "Strangers Again" and "(It's Always Gonna Be) Someday." MTM subsequently went bankrupt, and Dunn signed with Warner Bros. for 1989's The Blue Rose of Texas, which produced her first-ever number one single, "Are You Ever Gonna Love Me," as well as the Top Five "There Goes My Heart Again."

Released in 1990, Heart Full of Love spawned another chart-topper, "You Really Had Me Going," and Warner followed it with the hits compilation Milestones in 1991. (One of the new tracks, "Maybe I Mean Yes," sparked controversy over its lyrical content, which some interpreted as an apology for date rape.) Dunn's popularity took a hit with 1992's Getting It Dunn, and she subsequently parted ways with Warner. She resurfaced in 1995 on the smaller River North label with Life and Love and All the Stages, and was back on a major (A&M) for 1997's Leave One Bridge Standing. She retired from commercial music in 2003, citing changing times and an interest in painting, releasing only the gospel album Full Circle before leaving music. She died of ovarian cancer in Albuquerque, New Mexico in November 2016 at the age of 59. ~ Steve Huey