Cersei might not be good at war and fighting, but she knew history well. The North was near impossible to take from the outside by force or without treachery. And House Stark had endured plenty of both so they would be wary of such tactics. If she could not bring them back into the fold with a sword, she would do so with the greatest weapon ever- the one between a woman's legs. Robb Stark was easily laid low by an essosi whore, and Jon Snow would easily fall in the clutches of a lioness. And if her daughter was there, she would retrieve her too. Myrcella's place was with her, here in Casterly Rock.