I can understand wanting to be left alone and doing the work assigned to you without interruption, especially once you get the gist of the duties in your job. Coming across something unfamiliar or forgotten during training would be a few exceptions that one would go to a senior for assistance.
Not only was this girl really bad in personality, but I don't see her being the type to submit defeat and rely on someone for help, which could really hasten her time there before getting fired from poor work quality if it weren't for MC being meddlesome. At this point, if she was so insistent in being left alone, I'd back off if I was him and let her reap what she has sown, let her have a taste for where that toxic pride of hers will take her and see if she can learn to get back up after taking a great fall, unless a manager or someone similar said otherwise.