My sister has been diagnosed with glioblastoma multiforme and she's been alive more than 3 years since. is she doing well or does she have no time left?

Hard to tell: Sorry to hear about your sister, but it sounds like she is well into several years of survival. Gbm is an aggressive diagnosis, and many patients do not make it to the three year mark. While many families and patients want to know the "time left, " it's usually impossible to tell. We in oncology believe it's more about quality than quantity; hopefully her quality of life is ok. Best wishes.