What do you suggest if my grandmas been feelin sad lately and today she got a ct scan and they found cancer in her brain :/ will she most likely die?

Depends: This depends upon exactly what was found on the scan. There are some forms of cancer that can be removed. Others are very slow growing and may not cause issues for a long time. Others come from other parts of the body and reflect a part of an overall process. Should follow up with doctor to have questions answered on what she can expect and what the next step should be.