Some clots are due to Abnormal blood vessels bleeding in the brain, therefore surgery would be recommended in some patients to remove the abnormal vessels. It is important to rule out this cause. In this case other treatment options may include endovascular procedures rather than brain surgery.
Many patients can recover without surgery depending on the clots location and if the blood clot is stable in size and not expanding. The brain will eventually absorb the blood clot.
Regarding your mothers age of 65 years. She still has a long life to live. If surgery is indicated or recommended by her neurosurgeon, then the chances of a favorable outcome are in her favor.