Alongside Melanie Brown, Melanie Laccohee (later replaced by Victoria Adams), Lianne Morgan (later replaced by Melanie Chisholm) and Suzanne Tinker (soon replaced with Geri Halliwell), Stephenson completed the original 1994 line-up of Touch receiving the highest scores at the audition. At the audition, she sang Dina Carroll's song "Don't Be a Stranger". Stephenson was a member of the group for only a short period before commitment issues prompted Heart Management to remove her. Stephenson says that she left because her mother was suffering from breast cancer. "To say I was turfed out of the group when I left because I wanted to be with my sick mother – well, what kind of person does that?" She was replaced by Emma Bunton.
Stephenson has given several interviews about her time with the group, saying the she does not regret leaving them.
Stephenson worked briefly as a TV presenter for LWT,ITV, Friendly TV and BSkyB. She also filmed a TV show in Malta called Wild Games before forming a songwriting partnership with Ben Hackett and Mike Edwards (under the name SHEsongs). She has also worked as a session singer for various record companies. She performed backing vocals for singers like Ricky Martin and Julio Iglesias, while working on her own songs as well. In November 2003, Stephenson recorded and released an EP entitled SHESongs, featuring six songs called "In Control", "Fall Over", "Hey Sugar", "Dirty Music", "Boom, Boom" and "Happens for a Reason".