What were you shooting the gun at? The dog has to decide whether or not the noise bothers them. It's best if the dog sees something to retrieve and associates the noise of the gun with a bird falling. What method are you using to train your dog? You admit to not having done much with her for 2 years if I am reading the post correctly. Work with her. Start retrieving. Read a booK on the subject. Watch a video. You can find them at the library. A 5 week old pup is too young to remove from mama so that shouldn't be an option. If the instinct is there and she wasn't too tramatized, you could work through this.

Dr Fatguy