Are new fears after a stroke common?
Having new fears after a stroke is certainly possible. The brain is made up of many small areas that each control a specific function. For example, one area controls moving your left thumb, another area controls temperature regulation, and another area controls sensation in your right foot. There are also areas that control behavior and personality. Therefore, it is certainly possible that a stroke causing damage to a behavior or personality center would cause these phobias.
As with all symptoms after a stroke, slow improvement out to roughly six months from the time of the stroke is the rule. After six months, improvement slows down substantially.
Your aunt may benefit from behavioral therapy. This would be coordinated by a Psychologist (usually) and involves working on fear control when presented with a stimulus. If you think she would be interested in trying this, I would recommend asking your local doctor if they can refer you on to a Psychologist who is skilled at this therapy. If your local doctor does not know of anyone, try calling around to local Psychologist's offices and asking if they know anyone who uses these techniques. Good luck!
