I think she just couldn't give the order.
As much as Cersei hates both her brothers, she was taught by her dad that family is the most important thing. She's constantly been angered by her family's decisions and felt cheated by their deaths/murders that I don't think she could bring herself to take out Jaime too. Then she'd lose the high ground on the both of them.
Not to mention the fact that he's developed into her annoying conscience. She won't kill him for it, but doesn't want him around anymore.
Of course this ignores the fact that her murdering her son's wife was the motivation for him to kill hilself but I'm guessing she's rationalized that as being someone else's fault.
|