I can understand why the boutique owner wants to be the only one selling the bows, she doesn't want any competition and mostly if there is a small town and the stores are close by. But she doesn't have the right to get involved in your other business like website, craft shows and so on.
Maybe you can set a trial period and see what happens, ask about her sales. Are you familiar with the store?
Whatever you decided, good luck, and keep us posted.