Hi Christie,
It must be very difficult for you to be so far away from your Mother when she is so ill. But I think the hospital is probably doing all they can for her since she prefers to return to California for her treatment. What does your Mother tell you about what she is hearing from the docs? She probably doesn't know much either, since no further testing has been done. Does she have any friends in Chicago or has anyone gone there to support her while she is hospitalized? There isn't much you can do from the UK except call her and be there for her if she calls you.
I will keep you and your Mother in my prayers. Good luck to you both.
Joan L