It sounds like she tried to distance herself from you by moving her desk and now she is being intrusive again. You must have a leave me alone face. It's a face that says I am not in the mood for a conversation. Don't give cop out answers and just say you have to work or you don't want to discuss it. And if she insists just stare at her face. Soon she will go away. Since she is a coworker and you can't avoid her and being outright mean may not be advisable. If you want to clear the air then be straight up with her in the presence of two witnesses. This means ask two other co workers that you trust come with to the break room and invite this person so you can have a discussion. Most ppl leave you alone when you tell them too cause their feelings get hurt. She probably thinks you guys are great friends. There are ppl who won't listen but baby steps. Also her remembering details shouldn't be weird. Some ppl have good memories. The constant questioning that you are not uncomfortable is the issue. Has she ever met your fiancé? Or tried to contact him? How long have you known her?