Presumably, the banker wants to meet Moll in Brickhill because he wants to marry her
before taking her back to London. That way, when he brings Moll home, she is already his wife, and he won’t appear to be fooling around with a woman he isn’t married to, which, in the eyes of society, would reflect poorly on his own morality. However, the banker makes his plans without consulting Moll, which again illustrates how little agency women have in their society.