Recent diagnosis of aggressive lung cancer - fluid on lung build up

My mum was last week diagnosed with aggressive lung cancer, she had fluid removed last week from the lung lining which improved her breathing for a few days, but the benefit seems to have stopped and her breathing is as painful and ragged as before.

my question is:

How quickly can the fluid build up again following drainage?
should I contact nurse to book mum in again this quickly, or wait for her next appointment with consultant which could be another 2 weeks?

I don’t want her to suffer unnecessarily, but she ‘doesn’t want to be a nuisance’.

All constructive replies welcomed

Thank you for reading