sister with secondary cancer

hi all im new my wonderful sister who is 48 met me for coffee recently and told me her breast cancer is in the bones and her time is limited .I do not know a thing about cancer and i am totally struggling .I am hoping she is wrong can anyone PLEASE tell me the truth .She began with breast cancer 2 years ago ,had chemo then breast removed and radium after the operation it was discovered that they did not get a clear wall dunno what that means it travelled to liver where she had modules ,she has got small dose chemo but has never beeen totally away from chemo.Now her bones can anyone please shed some light please .She is so amazing and told me where she wants to be laid to rest ,Im not ready to loose her and am so afraid of telling my daughters who adore her ,please can anyone tell me what i dont know