why is mattie anxious about zeena

Ethan and Mattie settle down for a quiet night by the fire, Ethan with his pipe and Mattie with some sewing. Despite the fact they are alone and this would seem like a cozy almost romantic situation, the lingering chill of Zeena affects both of them. Mattie is uncomfortable at Zeena's position at the table, and she soon returns to her place at the table, pleading that the firelight is not bright enough for needlework. At first, the conversation seems to go easily. They talk about the goings-on in town, and they discuss the possibility of sledding ("coasting") some night. Ethan pulls his chair up to Mattie's table.