What Is The Prognosis For The Malignant Brain Tumor At An Elderly Age?

My mom has a malignant brain tumor. It was the size of a softball and she had 60%of it removed. they think it is a oli type but it also looks like it could be mixed. I was wondering is it more likely to be level 4 cause of the size or if it is a mix? and also was wondering what to expect as far as prognosis with her age of 66?