Stage 3b life expectancy without treatment

My 89 year old Mum has stage 3b squamous cancer of the oesophagus with 2 lymph nodes affected, palliative care only. She lives very close by and lives alone. She was diagnosed end of July and is very weak I find it so frustrating I don't know how long we have left with her. Do we being Christmas forward? Should family further away visit? I can see her weakening and I know she is thoroughly fed up with it all.