Its clear that the Queen wants the Salvatore family to fall. It doesn't concern Leslie at all, just that she's now involved and used as the weak link to try and bring down the Salvatores. If anything, I believe the Queen is threatened by the Salvatores and now that they have a female member that isn't set to be the head of the household, its possible that the Salvatores, with their prestige, can easily marry into the Royal family over someone of the Queen's choosing, someone like the weak minded Sperados that she can control via blackmail and manipulation. You could see how easily manipulated and weak willed they were just for power and the Queen can use that to maintain her power over the royal court even if she's no longer the Queen after the Prince steps up as King.