Agatha is a traveling merchant.
The large kitchen knife strapped to her back is not a weapon. It's a keepsake from her grandmother who was a great cook. People do get frightened by the huge knife though. As a result, no hagglers dare to bargain allowing Agatha to maintain a high profit margin.
She has long hair that almost covers her eyes, which makes herl ook creepy. It's not a fashion choice - she simply doesn't have time to get a haircut.