From what I recall, which shouldn't really be taken as what happens more often than not, but whatever...Either in the Spoiler/Robin special 1 shot or one of the first issues with her back there was a flashback with Bruce basically telling her that in the event of his death/disappearance (remember this was all during the big RIP fiasco where Bruce thought he was losing it and was going to die soon, so on and so forth) that she was supposed to help Tim become the protector of the City. He had some plans to help achieve it, and knew that in the event that words gets out that Batman is gone the gangs are going to rise up and it's going to become a much darker Gotham, but it was mostly him just giving her guidelines of what to do, and her doing them then adding her own little spoilerisms to them and causing a lot more grief than it was worth. She was, essentially, the one keeping the bad guys 1 step ahead of Tim's 3 steps ahead, but was told to do so by Batman.