20 year old girl with stage IV stomach cancer

my 20 year old sister got diagnosed with stomach cancer after several months of complaining from stomach pains, nausea and heartburn and getting full too quickly. she got very bad stomach pain which led to her getting hospitalised after weeks of her not being able to eat and doctors testing when she eventually got diagnosed with stomach cancer. We decided to start her chemo straight away and she didnt HAVE too many side effects at the begining but with time it got worse. she had unbearable stomach pain which led to her getting hospitalised again. The inital plan was for her to have surgery after 3-4 rounds of chemo but when they opened up her stomach they saw that it's way too advanced and has spread to many of her other organs including bowel, kindey and all around her stomach. The surgery was unsuccessful and now they are saying she will get another round of chemo in a month or two. Is this going to be palliative chemo? now she has lost her appetite and left shoulder hurts a lot. Is she losing the battle? is this the end of her life? she is nauseas and very tired and can't get out of bed. When she gets extreme shoulder pain she can't breathe properly. What is happening someone please help.