Estinien can't claim to be a master at reading people, but her reaction really does seem sincere. She could be a master manipulator of some sort, of course, and he can't completely shrug off Eponine's concerns, but he doesn't think Nadine knowing why Eponine ran off will put her in meaningfully more danger.

"She seems to be unharmed for the moment," he says. "But, she also seems convinced that you only brought her along to Nott to kill her. That another of the girls you brought along with her said as much." He shakes his head. "For what reason, I'm unsure."

He hesitates for a moment longer before adding:

"The girl has caused me considerable grief, but she deserves better than to be back on the street, begging for food. I'm sure you know how fragile her perception of the world is. Whatever was said to her, it has broken her heart."