No, I can't leave my Pa. He raised me by himself when slavers stole my Ma, when I was a just a baby. He's too sick to look after himself. I wish I knew something about fixing people. Cars are much easier. You just have to find the problem and swap the parts!
Casey's services were needed by the Brotherhood of Steel, after their own lead mechanic, Cooter, died in an accident. She had some sort of a relationship with Angry Rick. When she is found by the Warrior, she agrees to join the Brotherhood only if her father, Stephen Barrett, will be healed. He is very important to her. He raised her all by himself since she was a baby after her mother was stolen by raiders. Later, she can be found in Bunker Delta, being very happy to do her new job and even planning to become an initiate.
"Wow, are you who I think you are? Oh God, look at me, I'm a mess. Anyway, I'm Cassey, the local mechanic, it's a pleasure to meet you, warrior! I heard that you guys know how all sorts of stuff works. What? You want me to join? (pause) I'd like to, but I don't think you understand how sick my Pa is. He got shot in the first Reaver attack and I think it's infected. Last night his tongue started to turn black and then he messed himself five times. And guess who had to clean that shit up? I wish there was a doctor in this town."
"No, I can't leave my Pa. He raised me by himself when slavers stole my Ma, when I was a just a baby. He's too sick to look after himself. I wish I knew something about fixing people. Cars are much easier. You just have to find the problem and swap the parts!"
"You did it! That's great! I'll tell you what, I'll check him in the senior citizen work farm. The fresh air might do him some good and I'm getting really tired of wiping his wrinkly ass anyway. He did always tell me to follow my dreams. Just let me pack up my things and I'll meet you back at the bunker."
"Hey stranger! This place is great! I can't believe the equipment you guys have. I've seen maybe three cars in my whole life, then I come here! Big mechanical toys all over! I can't even begin to thank you! By the way, I'm starting basic training any day now. Who knows? Maybe the next time you see me, I'll be Initiate Casey Barrett."