Answer: it seems as though she is imagining her soul as an actual individual rather than a part of herself she deems the soul a “friend” because she believes it isn’t her or she may deem it a spy because it follows her and watches her because the soul is a part of her a soul secures itself because it protects itself from the world gives her a sense of humanity within her own
This is probably referring to the use of the “soul” such as insecurity and doubt, it can hurt or heal you. In simple terms, an double edged sword that lies within the mind is the mind itself, or as Dickens refers to it, an “soul”.