Is it obligatory for someone who is wronged by her superior due to her kindness and dedication at work to perform like her colleagues who do not fulfill their duties, or should she seek her reward from Allah?

The official must fulfill the duties of his position. If his superior wrongs him, he should resort to legitimate channels for grievance. If he does not obtain his rights, he should still fulfill his obligations and ask Allah for what is due to him, entrusting his affairs to Him. He should pray to Allah to grant him victory over those who wronged him, for there is no barrier between the supplication of the wronged and Allah. Allah gives respite to the oppressor, then seizes him with a painful and severe grip. The injustice of a superior does not justify abandoning the truth or remaining silent about falsehood if one is able to speak out. It is not permissible to emulate employees if their actions are unlawful. Rather, what is required is patience, supplication, and pursuing legitimate means of grievance.