When they're young like that, and you want to rid them of being gun shy, get some blanks and take a good distance away, maybe 100 feet, and fire them off as she's eating.
Over a matter of a couple of weeks get closer as she's eating her dinner and shoot near her and she shouldn't have a problem getting used to loud noises. Also have your lady stand near her while doing all this.
Somebody might have some better advice for how to properly handle this, but that's how I did it with my lab. Shame I never broke him of his hardmouth, and his retrieval skills are sub-par, if he wants to eat the dove or quail before getting it to you. But he does get excited when the guns are out and they're firing!