Veinslsher
Well they can be an important part of the storyline.
Sure, if she was originally intended to be part of the story as an important character. And if she was supposed to be, she would've already been made. Now, the following isn't aimed at vein's post, but at this concept in general.
We really don't need any characters who take the place of NPC's. The NPC's are NPC's for a reason, and that's to make all of our lives easier. I understand that characters tend to take their own turn, but we don't need her. I know we had Roy, who took the place of the nurse NPC, but he doesn't really pop up much. We all get amused by his antics, sure, but really he just takes up space. And this is no offense to the person who created him and not just something to be mean. It's a fact.
If you want to make your librarian, that's perfectly fine with me, but don't try to stick her in places where she isn't needed. She should be about a scarce as Roy.