The girl group recently reunited to embark on a greatest hits tour of the UK to celebrate 10 years in the music business.
Speaking about the shows, Harding told This Morning: "We are still in rehearsals at the moment.
"We've all kind of had our solo projects and interests that we wanted to pursue.
"But we've all come back and we've grown up a lot more, we're a little more diplomatic and have a lot more say."
The singer is currently promoting new movie Run For Your Wife, which sees her star opposite Danny Dyer and Denise Van Outen.
"Everyone seems to think I just want to take off and be an actress and I love to act, don't get me wrong, but I love my music," she explained. "It's in my blood."
Run For Your Wife will be released in UK cinemas on February 14, while Girls Aloud will start their headline tour in Newcastle on February 21.
Watch the music video for Girls Aloud's 'Beautiful Cause You Love Me' below: