The MC knows that she has to avoid the death flags or she will most probably die. She knows that the necklace her brother gifted her in c1 is a death flag trigger, if taken to the upcoming meeting and handled improperly. So obviously you leave it at home and just pretend you forgot or lost it, to avoid any problems, right? Well of course she takes it with her to the meeting. Now, this would be fine, if she kept her mouth shut about it, hiding the pendand. Easy, you say? Not so for our MC, the second she is asked if she is "... holding some special ornaments...?" by the brother of the girl that killed her in the future because of said pendand, she immediately shows it to him and tells him everything about it, including the death flag trigger. This happens at c3. Did I mention that her mind is that of a 18 years old?