((I wanted to specifiy: it was a very kind offer and I'm flattered. Brave Reaver is sometimes too shy but might just need a kick to become greater. She just won't admit her own strengths sometimes.))
I'd say take anyone else if they volunteer, but you can promote Brave Reaver if you think she'd be a good officer.
Also I nominate Yataka Shimaoka's character if he has one (I'm not sure)((if not, you should getcherself an officer)), and also Bullet Designer.