Is it permissible for a female student to pay money to her colleague in exchange for covering her shifts during the امتياز (internship/residency) year due to pregnancy, and what should she do about what has already transpired from this transaction?

This action is wrong because the internship year is considered an integral part of medical studies. It is an act of negligence and deception for a doctor to appoint someone else to attend their on-call shifts on their behalf. Deception and treachery are forbidden, and the Messenger of Allah, peace and blessings be upon him, said: "Whoever cheats is not of me." The questioner should have submitted a medical excuse for her absence. Now, she must seek forgiveness and repent, and either attend in person or postpone this year.