Please help,need guidance, advice, opinions, anything

Where to start, this is such a complicated and long story. My mother, my best friend, my absolute everything was given four months to live yesterday with radiation on treatments on brain. The last several years I've watched this women suffer and be put thru hell and she has fought and fought! My mom is 63 years old. In 1991 she has a total hysterectomy for cervical cancer. In 2015 she was diagnosed with anal cancer. She did several rounds of chemo and radiation and was cleared of tumors but the damage the radiation had caused her left her very very sick for about half a year, throwing up constantly and severe stomach pains. Finally in March of 2016 they figured out her intestines had been badly melted and she required surgery to have a temporary colostomy bag. During that operation she developed a blood clot in her leg from her legs being in stirrups for several hours. She laid in the hospital for five days screaming in pain, five days later she is sent to a larger hospital and they have to amputate it, several more complications occur during this time but not relevant to cancer. Finally Nov of 2016 she goes in for surgery to reverse the colostomy bag. After surgery for several days she was short of breath which wasn't normal. They find out she has a collapsed lung and tons of fluid in the other requirng at least three procedures. Thanksgiving we are told that she has stage 3 non small cell lung cancer. She does several rounds of chemo and radiation again. The most aggressive form of both. Aug 2017 we are told the tumors are gone. Thanksgiving of 2017 she falls (she's an amputee remember) so his has happened before. Well this time after she falls she is acting strange so she is taken to urgent care to make sure she didn't hit her head when she fell. The do the scan and tell us she has two brain tumors and would be transferring her to a larger hospital. She is put in icu immediately because of swelling on brain. This is Thursday. On Tuesday she undergoes brain surgery to remove small pieces from the largest tumor to reduce some swelling. We are told there are several tumors. Stage 4. A week after surgery she is sent to a rehabilitation hospital where she spends three weeks. Then to another rehab/nursing facility where she is currently. Yesterday a month and one day after her brain surgery we are told she only has four months to live possibly six but this is with radiation to the brain and it comes with devastating risks. I'm so devastated. I'm not ready for her to go. I'm begging if anybody has any advice any hope anything. I'm begging from the bottom of my heart please help. Thank you for reading,it's long, I know.