Each stroke is different and the amount of damage can vary widely. There is no way to be able to second guess what the doctors will say. Being in a coma right now is a good thing. Extended comas, on the other hand are not so good. While in a coma her brain will have a chance to heal but it really depends on how much damage has taken place. No one on this forum can give you any advice as good as what her doctors can give you. Chances for recovery can range from 1% to 99% as there are many factors that have to be considered and there is no such thing as average. You really need to talk to your family members about this.
Having an aneurism is often more lethal than certain clot type strokes are. Make no mistake about it, either one can kill. You might say it depends on how lucky the person is. Factors that determine survivability include location of aneurism, how large it was, amount of damage, the person's age and fitness, how quickly medical help was received, etc. The best chance for survival comes in the first 24 hours from the onset. Again, you need to talk to the family.
Best wishes to you and her family.