When people adopt young dogs, this growling problems may occur to many of them very frequently. The thing is that the dogs show aggression to their new owners by growling at them or anything that is around them. Little puppies usually do not do that to their owners, as they get trained at an appropriate age. You should study your dog's behavior in terms of eye contact. Does she stares at you or growl more aggressively when you look at her? NEVER stare back if so. This leads to further complications in the dogs behavior. Take her to a proper trainer if she keeps on growling at everything. She needs to be treated for her aggressiveness.