Jessen's biological mother was 17 years old when she sought an instillation abortion at 30 weeks of pregnancy. The abortion procedure failed, and Jessen was born alive and premature, with severe injury that resulted in physical atrophy and cerebral palsy. Subsequently, Jessen's biological parents, each aged 17, put Jessen up for adoption.
Jessen is a vocal pro-life advocate, and has spoken to both Congress and the House of Commons.  She has made a startling physical recovery; she was not expected to be able to walk, but she now walks with a modest limp. She entered and completed a local marathon in 2005, and the London Marathon in 2006. Jessen also sings, accompanied by her friend Michael Logen, and has written and recorded songs.
A 1999 biography of Jessen was written by Jessica Shaver.
On May 8, 2006, the Colorado State House of Representatives voted on a resolution honoring the 90th anniversary of a local branch of Planned Parenthood. Republican Representative Ted Harvey invited Jessen, whom he'd met as a singer, to sing the "Star-Spangled Banner" on this particular day, on the pretense of her being a cerebral palsy advocate.
She was greeted by applause for her singing and her inspiration as a cerebral palsy advocate. Attendees' reactions quickly turned to surprise when Harvey admitted that this was a secondary reason for his invitation. According to Harvey, his words were, "Members, today we are going to recognize the 90th anniversary of Rocky Mountain Planned Parenthood ... I just wanted to put a face to what we are celebrating today." 
Evidence of Jessen's own response is mixed; The Denver Post reports that Jessen "didn't expect it," but "was glad Harvey told her story." Later, in January 2007 when she was interviewed on the Eternal Word Television Network's Life on the Rock program, Jessen related the entire story (beginning at the point where Harvey first approached her at an earlier event where she appeared) expressing pleasure at her function in this event, and making no suggestion that she hadn't been a fully willing and informed participant in Harvey's plan.
On September 15th, 2008, Gianna Jessen appeared on "Hannity and Colmes" on the Fox News Channel to tell her story.