In the story of "Marigolds," the character Lizabeth is motivated by a sense of jealousy and resentment. She is jealous of the wealth and privilege of the rich family who lives across the street from her, and she resents the fact that her own family is poor and struggling.
Lizabeth's motivations are revealed through her actions and words. She is angry and bitter, and she feels that the world has treated her unfairly. She expresses her resentment towards the rich family by taunting and teasing their daughter, who is her classmate at school. She also destroys the marigolds that the rich family has planted in their garden, and she takes pleasure in watching them wither and die.
Lizabeth's motivations are also revealed through her relationship with her mother. She sees her mother as weak and powerless, and she resents her for not being able to provide for their family. Lizabeth feels that her mother has failed her, and that she must take matters into her own hands in order to survive and thrive in a world that is hostile and unforgiving.
Overall, Lizabeth's motivations in the story of "Marigolds" are driven by a combination of jealousy, resentment, and a desire for power and control. She is angry at the world and at herself, and she lashes out in destructive and violent ways in order to cope with her feelings of anger and frustration.