Chicago is a wonderful place. It was ranked one of the most dog-friendly cities; there are lots of dog parks, a beautiful lakefront and tons of nice dogs and people for puppies to meet. However, Chicago's harsh, winter weather makes it a very challenging city to socialize a puppy in the winter months.
Dog Training Blog
I frequently work with fearful or aggressive dogs. They are grouped into the same category because aggression always has a fear component unless an animal is hunting for food. Fear aggression manifests itself in warnings to tell the other dog or person to stay away. A bite is a more intense warning if the other warnings, such as growling, go unheeded.
One of the more frequent issues with shy dogs is to be afraid of getting petted by strangers. When dogs are getting petted the person is close to them, they are looking at them, they are looming over them and then they touch them. These are all potential triggers for anxiety or aggression. If your dog is shy, you should help her get comfortable with people to avoid escalation of anxiety, which could potentially lead to aggression.