Generally speaking it is likely that she was unconscious from the aneurysm and so a coma was induced to keep her under. Again, that goes back to the brain trying and needing to heal. It won't heal if the patient is combative or in pain. A coma will minimize the resources the body will want and will give the majority to the brain. This is all very normal treatment.
Like your heart and lungs, your brain never quits working and sometimes it needs a little bit lessening of the load on it. In simple terms the brain is a well-built computer than runs on electricity and oxygen. Any injury can interrupt the flow and cause damage. It doesn't take much to disrupt the functioning. So the less demands on it the better and faster it can heal if it is going to. One of the instructions to my wife from the doctor was to let me sleep as much as I wanted and not to be alarmed over the amount I slept. It's all perfectly normal, hence the reason for a coma. I think for almost the first year I slept about 18 hours a day.
Remember, I am 7 years post-stroke and the first 2 years were the worst. I still have problems and likely always will, they are just a good bit smaller than they used to be. Now most people can't tell unless thery talk to me. Sometimes I still can't talk very well.