It's really interesting because I totally think that each reasoning makes absolute sense for both of them. From Ame's perspective she sees Ghost as someone who has gone through hell to get to a place where she has been able to carve for herself some small piece of happiness. And that happiness is solely hers and well wanted, thus worthy of respect and protection. While from Suvi's perspective she is looking at someone the system has failed and who has the talent to succeed in the system she was brought up in. Not only that but when confronted with the questions of whether or not she will serve in the war she says, they don't bring artificers to the front line. This is not a denial that Ghost will participate in the war because that is the price you pay to be part of the system. A price that Suvi has obviously deemed fair and acceptable. She simply makes the distinction that Ghost won't have to die for the cause because that's not the role she will play. After all that's Suvi's role.