your friend only came her for two weeks. It is too early to do anything. I would focus on other parts during the report, and touch on the part that has problem as "this is a small part with lots of details", "I need to spend some time on it to understand it first".
The idea is to show the big boss that she is capable and ramps up quickly. First build credibility for herself, then decide what to do with the problematic issues later, over time.
Or ask the manager exactly what to do with the bad transactions in email, and do exactly as told. If asked later on, just say that I am not familiar with it, i did as instructed...
