@breizh It's not that she trusts him enough, it's that she knows he's weaker than her on top of being injured.
Just look at that massive gap in their athleticism, he wasn't even able to fight those neanderthals as good as her and was panting before they even attempted the jump. While this is probably a genetic issue on top of him being the average college student, you can't ignore that he's physically inferior to the point she looked down on him for not doing a basic task in their era.
So knowing this, you wouldn't care if a 6 year old slept nearby, would you?