What is the solution for the distress felt by the female student due to her feeling of injustice and favoritism, despite her excellence and intelligence?

The excellence worthy of competition and envy is that which is in obedience to Allah and drawing closer to Him, as the Prophet, peace and blessings be upon him, said: "There is no envy except in two [cases]: a man whom Allah has given wealth and enabled him to spend it in a rightful cause, and a man whom Allah has given wisdom and he judges by it and teaches it." What brings comfort to the conscience is for a person to look at those who are beneath him in worldly matters, as the Prophet, peace and blessings be upon him, said: "Look at those who are below you, and do not look at those who are above you, for that is more likely to prevent you from belittling Allah's blessings upon you." We advise the sister to strive in her studies without looking at what Allah has given to others. And if the teachers give some students more than their due, or deprive some students of their due, then they have erred, because justice in awarding grades is obligatory. Excessive preoccupation with these matters leads to anxiety and disturbance.