The star explained that she was never at war with "lead singer" Coyle, adding she made no secret of her desire to launch a solo career in the US.
"It was no secret Nadine was trying to launch a solo career in America," Cole writes in her autobiography, Cheryl: My Story.
"She'd been living in the States for several years by now and was forever travelling back and forth. I felt we were lucky she was prepared to split herself in two."
Describing the group's final months before their hiatus in 2009, she revealed: "This was different, though. Having her manager actually on tour with us was crossing the line, and that's when I knew that it was finally time for us to take a break."
However, Cole insisted that she always "gelled well" with Coyle, adding: "I think we all expected her to come up with some sort of excuse, but she actually just admitted, 'It's not really my thing' (2008 Brit Awards)."
Coyle recently stated that she never wants Girls Aloud to break up after being spotted at Cole's arena gig in London earlier this week.
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