When the knock came on the door Ruby had an idea it would be Martha. She knew Dean had talked to the doctor and invited her to examine Jo. And weren't doctors supposed to have some kind of bedside manner. Ruby could only assume that meant she'd be better at the whole talking to Jo thing, helping her deal with her grief. Making sure the kid was okay, if there even was a kid. It was better that she was here, she could figure all this out and hopefully would know what to do for the best
She moved to quickly open the door, admitting Martha, she would have been checked on coming into the camp and she wasn't a demon. Ruby would have known instantly if she were. So that was enough for her to explain what she knew to the woman. "She's just been lying there. Shock I guess. Is it going to affect the kid, levels of stress like that? Anything I can do, or should I wait outside. Up to you?"
She didn't mind waiting outside if that was what was best. In the grand scheme of things it didn't matter much of course. They were all going to die. They were all going to suffer for Lucifer's arrogance and hatred of humanity. The poor kid probably wouldn't even get born. But until she had to walk away from Chitaqua she would be there for her friends.
While she could. She supposed while Lucifer let her.