Unfortunately, after the band was formed, they were interviewed on camera and Nadine was quite willing to talk about herself, but during the interview she stopped suddenly when she realized that she had given the wrong date of birth to enter the competition and could now no longer remember what she had originally stated was her date of birth. She later broke down off camera and admitted that she had lied about her age, and was in fact only 16 years old.

The competition rules demanded that the contestants be at least eighteen years of age. Nadine was ejected from the group.

Since Nadine’s huge success with the group, Louis Walsh has promised to make Nadine a solo star if and when Girls Aloud go their separate ways. However, she has constantly denied reports that she will leave the girl group to become a solo artist. During Girls Aloud's promotional tour of Australia and New Zealand in February 2006, Coyle met Desperate Housewives actor Jesse Metcalfe and a relationship was rumoured to have begun, although Nadine has denied the rumours.