Hello Presh1968.  So sorry to hear about your Mum.  When my own Mum was dying of cancer I asked her Oncologist how long she had left, and he told me she had 'about a week'.  She died 3 days later.  You could ask her medical team how long she has got.  They will have a rough idea of the time frame.  Although I have to say that sometimes a cancer patient has a lot more or a lot less time than their medical team thinks, but in the case of my Mum, they were pretty much accurate.  If you think that you can handle the truth, it is her Oncologist you need to speak to.  Once again, so sorry.   

It's difficult. First, it IS difficult to predict and second because of that it is difficult to get an answer. Senior medics wouldn't commit at all when my wife was discharged palliative-only. I rather brow-beated a more junior doctor into going as far as "not months". She died within 6 weeks.

Thank you for replying and for your kind thoughts, I’m sorry for your loss, she hasn’t been placed in palliative care as yet, and certainly doesn’t appear to need it currently, but all we have been advised is that that is the only treatment now available as she doesn’t want an operation or chemotherapy.