Deruo,
Waiting is such a terrible added stress to what you and your mother are currently going through. I agree, try to get on a waiting list for cancellations, and call every day (the proverbial squeaky wheel). If her coughing and breathing continue to deteriorate, run, don't walk to the nearest ER.
I was "lucky" enough to have been admitted to the hospital because of severe shortness of breath when I was initially dx with SCLC, and my chemo was started within days. As said before, SCLC moves very fast but it usually responds very well to chemo.
Hoping things go well for you both, keep us posted.
Mary