The Tesco checkout worker said that she would be performing 'All I Want Is You' from the 1988 album Rattle And Hum.
She also stated that there would be a Rock Week theme to the show. However, theme weeks have been altered at a late stage during the series and it is not usually confirmed until Wednesday evening when Matt Edmondson's F Factor blog is published on the official site.
All seven of the remaining acts will be singing two tracks on Saturday night in an extended show, which will kick off at the earlier time of 7.45pm on ITV1.
Meanwhile, Sunday's results show will feature performances from Justin Bieber, Nicole Scherzinger and The Wanted.