That's their brand and they play up to it. Same as most of them. Nicola's playing to her bitch brand...she openly says it. Even boring Calum was playing to his "I'm a gentleman" brand.
You either like them or you don't. Personally, I'm not on the pro-Jedward side (they annoy me to no end) but I'm on the anti-Nicola/Coleen side.
What's that saying? "The enemy of my enemy is my friend" (or something like that).