My mum is dying

Hi everyone my mum as melanoma cancer stage 4, im devasted as my dad also batlled with cancer but he is still going with regular check ups but didnt expect my mum and so advanced she did a biopsy and waiting on resultads but is getting worse by the day for now we know is on the bones, lymphnodes and lungs but is spreading fast and she is in bed,not eating just drinking the proteins drinks, very yellow skin and with medication for the pain, she is sleping all the time now as a swallen side of face and eye, they taking too long that type of cancer progresses very quicly i keep seeing this as her last symptoms as anyone had a similiar case, im so worried that when the results come treatment will be to late or she is to weak to do it, sorry just need to talk to someone with similar experience a little advice, anything... i dont know what to do to help her.