Post brain surgery, healing time, and Kemo/radiation treatment for liver..

My sister has stage 4 breast cancer. Treatment has eradicated the tumors in the breast. 9 lymph nodes have also been removed. Lesions have been found on her liver. Treatment had also reduced the lesions. Now, 6 months after her "clean bill of health", she recently developed a brain tumor in her cerebellum....and lesions are covering her liver. Three days ago she underwent brain surgery and the surgeon successfully removed all of the tumor however her liver enzymes have doubled from normal and with all her meds, her sugar level is 350 (she is diabetic) and blood pressure is high (not sure what the numbers are). I'm scared of those lesions covering her liver. The doctors say they can't treat with radiation or kimo or anything until the substantial wound from her brain surgery is healed. How dangerous is it to wait? Does anyone have an experience they can share?? Any input would greatly be appreciated!!
Thanks!!