She tried her solo career in the US in 2007, 2009 and most recently in 2011 with the X Factor US, but the other girls from PCD sabotaged her image with stories etc, which may or may not have been true.
Either way it damaged her reputation in the US, and she was largely seen as the person to blame for the split of the band which was a shame.
I think she suits the UK though, she obviously loves it here, her boyfriend is British and she seems to fit in very well, especially with the X Factor last year. I'm glad she has a successful solo career here. She's stunning and talented.