Guitarist Kay Russell became her songwriting partner throughout her career. Both women wrote lyrics and melodies together.
After impressing their future manager Alan Brown at a musical instrument shop, Fassbender and Russell signed to independent record label Criminal Records and wrote "Twilight Café", which was released in 1980. Two other singles followed soon after, namely "Stay" and "Merry-Go-Round" which were promoted on BBC TV shows Cheggars Plays Pop and Multi-Coloured Swap Shop.
After release of the latter singles, Susan Fassbender and Kay Russell both retired temporarily from the music industry, to marry and for Fassbender to raise three children.
An album of unreleased Fassbender and Russell demos entitled ''Twilight Café (The Demo Collection 1981–1985)'' was released through Platform Records on iTunes and Amazon on 30 April 2012, with a further album of demos, ''Building A Dream'', released in 2016.
Susan Fassbender committed suicide in May 1991, at the age of 32.