Yueler just wanted to be a bastard, but she knew how terrible war was, and when she was involved in this world, she couldn't convince herself not to help them.
So she was discovered when she chose to give silently!
Now it is impossible to just run away and continue to be a gangster after helping!
Snape had never seen anyone so similar to him, as if she should have died like this, but he was helpless that he did not die. When he saw those fragmented memories, when he knew that she was just for a meaningless excuse like "you saved me" (fake), he didn't even know when he had saved her, and when those black eyes stared at him like this, maybe his heart began to shake.
Purpose: Be positive and optimistic, don't be a bastard