Which opens up a whole array, incidentally, of decent ways for her to be written out of Barbara's life without making Babs seem like a more abominable excuse for a mentor than Oliver Bleeding Queen. Top of my musing list at the moment is "sent her to find Sin, investigate her situation and look out for her" - Misfit bouncing into the monastery is about the lowest-profile investigation humanly possible, no way the LoA is going to pick up on that, so Babs is getting the answers she needs and can't get from Dinah without putting Sin in any danger. Charlie then sticks around for a few months driving the monks insane just to make sure everything is kosher and it's a good place for Sin before coming home to give her report, at which point all the Battle bullshit will be over and some other writer has to deal with it.