She doesn't know why she thinks this is a good idea. Sina pads down the dungeon steps, barefoot as her cultural clothing dictates, and shows the guards her basket of herbs. She's allowed now and then to visit the prisoners with small comforts, salves for their bruises and packets to help calm upset stomachs or bring on sleep.
This is the pretense under which she now arrives, her anchor a green beacon in the hall she traverses until she comes to Atticus' cell. Rather than offer either of them any ministrations, she gets right to the point: "I know you."

(Fortunately for both of them, Benedict is asleep.)