I've been googling it. You can see what the Mayo Clinic says here.
There is such a thing as Health care-acquired pneumonia apparently.
Health care-acquired pneumonia is a bacterial infection that occurs in people who live in long-term care facilities or who receive care in outpatient clinics, including kidney dialysis centers. Like hospital-acquired pneumonia, health care-acquired pneumonia can be caused by bacteria that are more resistant to antibiotics.That could be the culprit.
Fluid accumulation around the lungs (pleural effusion). Pneumonia may cause fluid to build up in the thin space between layers of tissue that line the lungs and chest cavity (pleura). If the fluid becomes infected, you may need to have it drained through a chest tube or removed with surgery.They need to drain her lung but the fluid is too viscous, they have put her on antibiotics for a fortnight to see if that helps and they can try again.
It is all very worrying,