I'm writing a compare and contrast essay on Daisy and Gertrude and I am having trouble coming up with some contrast between them.
I would suggest that you contrast them in regards to the their attitudes about being mothers and their attitudes about the importance of their children. Daisy is aloof and treats Pamela like a bit of a pet and an abstraction, "a beautiful little fool." Gertrude on the other hand has a more genuine connection and concern for Hamlet. She doesn't want him to return to school; she asks Rosencrantz and Guildenstern to help discover what is bothering him; she takes to heart his condemnation of her marriage to Claudius; she keeps his secret that he is only acting crazy.
Another contrast would be to evaluate how their motives for marriage and remarriage/affair. You could contrast the quality of their first marriages and then consider what leads each of them to another man - how and why. Daisy seems caught up in the past, while Gertrude was more likely looking at her future.