Caleb was a survivor. After the bombs fell, she knew how lucky she had been to having skipped school and went to explore that old abandoned mine. Being underground saved her. Now, the few that survived roam in raider gangs or mercenary groups, with a few loners by themselves, but it's rare to see an 18 yo girl roaming the wastes alone. However the gear she packs and her skills at surviving should leave no doubt in anyone who gets to know her that she was made for this. Of course being distrustful of others means it can be a challenge to get close enough to find out
For this RP I'm leaving it fairly open as to where the story goes. My idea is that she would stumble upon your character, also a lone wanderer, but what happens next is up for discussion. Maybe they battle and then end up falling in love, maybe one tries to capture the other only to see the situation reversed, etc.