Sleeping 8 hours during the day

Hello

I'm full time carer to 88 year old Mum with advanced pancreatic cancer.

Does sleeping 8 hours during the day mean we are near the end? 

Eating and drinking small amounts. Has some pain in mid back.

I kinda know the answer but just needed to chat.

Thanks 

PS I'm very prepared and have all the meds and emergency numbers.