Uh, sorry chaps - I didn't mean AA. I actually meant banding. Maybe I misunderstand the term, but I sometimes see banding when just using a solid thick line of one colour. I thought the black outlines two pixels thick might look better if their thickness was less haphazard - that the lines looked to me as if they created some sort of banding effect with, well, themselves, negative space around them, sort of thing. I didn't know whether she'd know what that was, to then know how to clean them up properly after.
AA I figured she could well avoid entirely if she wanted to as a style choice. Some people insist on using thick lines.