If you were in this situation, how would you feel? Do you think Aubrey deserved credit for something for which she didn't do any of the work? Would it be fair to say Aubrey stole something from Melody? If their boss found out about what happened, should there be consequences?

In the case of plagiarism or stealing another person's work, it's never fair that the person taking the work receives credit. Aubrey is, in fact, stealing, and does not deserve credit for this action, but rather deserves to lose credit and be punished. Their boss should take consequential action against Aubrey for taking another person's work. In this situation I would be angry and would demand credit for the work that was stolen from me and for the thief to be punished accordingly.