Anna definitely recognized Rob. Once Cas had pointed out the family resemblance, it was hard not to see it. She thought that the other man in the hallway was vaguely familiar as well. The woman was clearly one of the intended victims of the serial killer. Anna put a hand on Castiel's arm to get him to lower his gun, though she was sure that he would do so soon enough at Rob's words.
She moved over to where the man in the hat was now holding the woman in his arms. She attempted to offer a sympathetic look to the woman.
"I can help you get her out if you'd like," she offered to the man who didn't look even a bit out of place in this era. They'd all shown up in the correct clothing, but this man had a face and a sort of posture that suited this time period, as if he'd been born in the wrong time. Or perhaps he was time displaced like Mary had been. It was hard to say, but it didn't much matter at the moment.
She gave Castiel a look as if to say that she didn't begrudge him continuing on. He had more of an emotional attachment to Mary and Anna was okay with seeing to one of the other survivors just now.