In the novel "Ethan Frome" by Edith Wharton, Ethan Frome is trapped in a loveless and unhappy marriage with his wife Zeena. However, he starts to develop romantic feelings for Mattie, his wife's cousin who has come to stay with them. When Ethan speculates that he would not have married Zeena if his mother had died in the spring, he is reflecting on how his circumstances and responsibilities influenced his decision to marry her. He believes that if his mother had died earlier in the year, he would have had the opportunity to pursue a relationship with Mattie instead of feeling obligated to marry Zeena. This realization suggests that Ethan believes he would have been happier with Mattie. He recognizes that his marriage to Zeena was not based on genuine love or compatibility, but rather a result of duty and the practical needs of the situation. Ethan's speculation indicates that he would have chosen a different path if given the chance, and this implies that he still harbors deep feelings for Mattie. In summary, Ethan realizes that he would have been happier with Mattie if his mother had died earlier in the year, as this would have given him the opportunity to pursue a relationship with her instead of marrying Zeena out of obligation.