She's lucky this isn't the world of Goblin Slayer. And no it isn't for the reason some people might be thinking. It's because she would get in serious trouble for withholding information about the dungeon, since she will get loot for defeating the boss. During a rank up examination she wouldn't be able to lie at all. During the interview depending on the questions, she would be in grave danger of being forced to reveal the truth about herself. Be it her past life or just about the boss she fought on her own. It depends on what the actual rules are, and if this particular situation would apply or not. Normally, you aren't allowed to keep items for yourself without consent. Period, if you're in a party. It's a serious violation that will get you demoted (most likely back down to the lowest rank) and banned from working in the town the interview took place in ever again. Keep in mind that this applies to the Goblin Slayer world, not this one. Not sure what the rules are here.