In my experience, chiropractic manipulation can cause strokes. There is a particular maneuver where the chiropractor twists the neck that can cause tearing of the vertebral artery as it runs
through the neck bones. However, to my knowledge, this typically would cause an ischemic stroke from a clot formation in the artery due to a tear. However, if the cause of your mother's hemorrhagic stroke was a subarachnoid hemorrhage from a tear of one of the arteries entering the brain, I think it is certainly possible.
Although I never like to assign blame to someone who is trying to perform a healing act, in the case of chiropractors, I think they need to stop performing this one particular neck manipulation, as I have seen some devastating strokes result from the maneuver. I have had a few patients who suffered devastating strokes as a result of this practice. The website chiropracticstroke.com provides some examples of such events.