Welcome to YT! I wonder if she could be jealous of your children. My Roxy was rehomed to me, along with Bubba, in part because she was growling and jealous of a new baby. Maybe your girl wants you to herself. Roxy who is now 7, and i have had them for almost 5 yrs, has started this growling now towards my cat - when she doesn't want the cat to join us on the couch.
I would suggest that you post about this with a descriptive title in the Training forum - hopefully someone who is more experienced with this will see your thread & answer there.
Also, perhaps you could sign up for some puppy training classes in your town |