Cosima looks slightly ill, but doesn't really feel she's in a position to object. Beyond traveling to the rift that got them here, she doesn't know Jaime or Lexa. And while she doesn't want to kill anyone, she even less wants to get them caught by slowing down the escape attempt - or worse, have them decide she's a liability and leave her behind.

Instead, she comes to help Jaime with his clothes. She's nearsighted, and she can manage close-up work like buttons.