"Yeah? Yeah. I think so." She scrunched her nose a bit, staring at River and then thinking over. The library? Oh! Oh... It was written on the expressions of her face how her mind was processing it all. This version of herself was pretty easy to read (unless she was being careful to hide her emotions- which usually didn't need to happen).
"That Library? But how...?" It was suspicious. Not that she was unhappy to see River (far from it!), but as far as she knew, she hadn't figured out how that could work. Well, robots. But that wasn't the same, was it? No, the Doctor hadn't quite solved that mystery. Though she had also gotten distracted along the way.
The ground beneath them shook and something in the device in the Doctor's hand made a loud beeping sound. Probably not the best time. She looked down at the readings on the device and frowned. "Well that's happenin' quicker than I expected. We should run. Now."
She grabbed River's hand without second-guessing it and started pulling her with her in a half-jog in the direction of the TARDIS. "You didn't come here with anyone, did you??"
Best to double-check to see who else might need rescuing, after all.