The third reason for leaving is that she was the one who created the mutants that Bushwick used to wear down the lamp bearers. She accomplished this by using her Rank 2 divine ability to curse captive godclads with the curse of a weary mind.
To a mortal, the curse of a weary mind will make them sleepy. They will feel groggy for a while until they lose consciousness and never wake up again.
Unfortunately for godclads, when their minds are cursed to become weak and they become unconscious, there is something within them that is willing to take control of their body for them. This way, she can induce the mutation of a godclad.
She told Bushwick to hide her involvement in his schemes. It is clear that he didn't tell her brother about her capabilities, but she can't count on him to keep her actions a secret forever. In fact, she expects Bushwick to use it against her sometimes in the future.
