Regina could only laugh because of how blind she was to Minnie's true personality her entire life. Weren't grandmother's supposed to be sweet? Minnie had mastered the skill of being two-faced. Regina underestimated Minnie even after learning that she had something to do with the death of her grandfather. No wonder her mother hated Minnie. The woman influenced too many decisions in the house.
Regina imagined five strings signifying the relationships she had with her family. She thought of this because of a woman she heard stories of named Atropos. The string she had for Minnie had just been cut which meant Minnie was dead to her. She sealed that deal by threatening to marry her off to a horrible man like Gilbert. Only four more strings remained but a pair of scissors was waiting at the strings for her brother and father.
'This might have something to do with why Samuel apologized to me,' she thought.