You want to stop that type of threat or it could escalate. If it happens again and if she's not play-fighting with you, no matter what her stresses, immediately correct her - stand up with a firm "No", stare at her and hold her gaze, point at her with your finger and move into her, backing her off until she gets down from the couch or bed, following after her and even standing over her for some time until you know she's gotten your message she was wrong to behave aggressively toward you and threaten you.
It should only take a time or two of that type of correction to get the strong message across that no growling at mommie is ever allowed in this pack. Growling in the circumstance you described shows some degree of distrust and is usually an attempt to take some control and dogs who are insecure or anxious will often try to control things they feel are out of their control. You want her to know you are always in control of what happens in your home and not she and you will kiss her or do whatever whenever you want anytime you want.
It's quite normal for dogs to have their moments when their lives are changing and up to us to guide them through it with correction where necessary should they act aggressively or threatening toward us as a result of their stress and maybe throw in some extra obedience training, maybe a week of a Nothing In Life Is Free program, extra exercise and life-enriching puzzles and games you play with them to help them re-orient themselves and their bond with us as their ever-trusted pack leader.
__________________  Jeanie and Tibbe One must do the best one can. You may get some marks for a very imperfect answer: you will certainly get none for leaving the question alone. C. S. Lewis |