A good thesis statement makes a claim with which another person could argue; it is not a statement of fact. It can also be supported with ample evidence from the text. It sounds as though you already have a good thesis embedded in your own question, where you describe your...
A good thesis statement makes a claim with which another person could argue; it is not a statement of fact. It can also be supported with ample evidence from the text. It sounds as though you already have a good thesis embedded in your own question, where you describe your topic. You say, "my topic is about how the oppressive behavior of her father is what causes her to lose her realistic perspective, which leads to her psychological problem." If we finesse this a little bit, you will certainly have a thesis.
It's always a good idea to reference the author and title of the story about which you are writing, so you might say something like the following: In William Faulkner's "A Rose for Emily," Miss Emily Grierson develops psychological problems and loses perspective on reality as a result of her father's oppressive behavior when she was younger.
Miss Emily's father has "driven away" all of the young men who came to court her so that, when he eventually dies, she is thirty years old with no more romantic prospects. His behavior, people in town believe, "robbed her," and so she has clung to his memory so as to avoid being alone. They also describe Miss Emily's father as having "thwarted her woman's life so many times," presumably by deciding that "none of the young men were quite good enough for" her.
Moreover, we can see the deterioration in Miss Emily's psyche after he dies and she refuses to accept that fact, keeping his body in her home for three full days and continuing to deny that he had passed. She comes to the door "dressed as usual and with no trace of grief on her face" until she finally "broke down" and let the doctors in. Later, the fact that Emily buys arsenic, fully intending, apparently, to murder her boyfriend, and then keeps his decaying body in her bed is further evidence of her mental instability. Her habit of keeping bodies clearly dates from her father's death.