Armstrong was born and brought up in Blackbird Leys, Oxford, England, living with her parents and one older brother Stephen.
Armstrong started her career as a dancer from an early age but when her friend, Kelly O'Keefe had work experience with a music management company and was asked to put together a group, she joined Deuce alongside Kelly O'Keefe, Craig Young and Paul Holmes.
The group decided to continue on a new label and O'Keefe was replaced by Amanda Perkins, for one single, before they disbanded.
In 2020, she was one of the Guest Judges on make up competition show Glow Up: Britain's Next Make-Up Star on Series 2, Episode 6.
On 22 July 2006, Armstrong married her long-term boyfriend Ant McPartlin at Cliveden, a country house hotel in Buckinghamshire.