Now, Coyle - who cancelled her UK and Irish tour earlier this summer - has spoken about her time in the band and admitted that the other girls 'didn't like [her]' because she was given more lines in their songs.
She dismissed the notion that the other members - Cheryl, Nicola, Sarah and Kimberley - were 'jealous', but told iNews that there was certainly some bad feelings between them.
"I didn't say that [they were jealous], how pompous and arrogant would I have to be to say that?," she said. "But yes, a thing that did cause stress in the band was the fact that I was given more lines.
They didn't like the label as a result of it, and they didn't like me as a result of it. So it was just circumstances which were out of my control. I didn't decide who sang what. But I love my life and I just get on with it."
She added that she would still be up for any potential Girls Aloud reunion in the future, saying: "The answer is always the same: if everything comes together, then yes, I'm a huge supporter of Girls Aloud. I'd never say never to us coming back together."
It looks like we may be waiting a while for that one...