At least he's moving, even if she's suddenly tempted to stop in her tracks. If she does, though, he's going to dig his own heels in until he wheedles another promise out of her. Getting him to the med tent matters more than having this argument out. So she keeps walking, keeping her steps a little slower than usual, for his sake. "I'm not promising that."

That's what they tried to do at the prison, run in all directions and find each other after. It worked out, as far as she can tell, but if she'd suffered for it, she's sure everyone else did, too.