Editors at eNotes cannot write your essays for you, but I'll be happy to give you a few pointers.
Although Mayella showed an uncontrollable desire for Tom at one time, the trial must have shamed her greatly. She may feel some guilt and remorse for the lies and disgraceful charges that she brings against Tom, but she may actually feel a relief that he is dead. Tom's death means the whole case will die away with him; there will be no appeal or publicized execution to bring the bad memory of the trial back to life again. Since Mayella is barely literate, I would use simple, elementary school-like language. She speaks in a Southern colloquial tongue, so such usage would also be appropriate. (Review the courtroom dialogue again before beginning your essay.) You probably need to decide if you are going to have Mayella confess her guilt, or if you are going to allow her to maintain that Tom was the guilty party.
Mayella is a lonely young woman trapped in a home with an abusive father and many difficult responsibilities. The family's poverty ranks them just one step up on the social ladder above blacks, a social position quite low. In writing through her voice, you will need to keep in mind that her poverty and social standing (in addition to her father's influence) leads her to hate blacks. However, her loneliness leads to to attempt to get any attention whatsoever from whoever will show it to her.
In considering Mayella's perspective who will want to decide on one of two directions: remorseful Mayella or relieved Mayella.
Remorseful Mayella would be quite sorry that she had lied in court. She would feel like Tom Robinson's death was her fault and would perhaps become a less racist and more honest person in the future. She might even admit her lies in order to clear Tom's name.
Relieved Mayella would be happy to have gotten away with her lies. She has avoided the social stigma of making advances toward a black man and certainly avoided the wrath of her abusive father. She might feel as if she has escaped justice this time and might be more likely to test it in the future. She would be aware that she can say anything she wants about a black person and, because she is white, be believed.
When writing your reflection, be sure to use the first person point of view as if YOU are Mayella.