The 31-year-old singer married Ashley in 2006 after two years of dating, but split in 2010 following accusations that the footballer had cheated on her, reported Digital Spy.
"You know what I also realised these past years? I refuse to let somebody else's behaviour change me fundamentally. I'm going to remain the person I am, with the values and beliefs that I had.
"There was no horribleness, apart from what happened at the end. My marriage wasn't bad. I wasn't treated badly. I wasn't a victim. We weren't arguing. Nothing like that. It was just weakness on his behalf, which is unfortunate, but it happens," she said.