Who sewed Hester's scarlet letter A?

Initially, in the world of the characters in the novel, the A stands for adultery. The meaning, however, changes as the plot progresses and some in the story regard the A as meaning angel. From the reader's standpoint, and taking into account that this is an allegory where every action, every character, every location means something in addition to itself, the A does not actually stand for adultery or angel but can mean just about anything.