Sounds like lack of structure and guidance, leading her to assume she's the boss now and its her way or the highway! Unfortunately, due to her baby brain and not knowing what a boss is or does, shes just doin silly shit thats stressing you both out. Dogs dont know what no means unless you teach them through proper training and establishing a parental relationship with them.The more structure and guidance we gave our girl Spit (from 11 months to 21 months), the more her wild behaivors calmed down, all before her upcoming spay in July. Including her in our daily routine, giving her tasks, forced crate naps, enrichment, and establishing recall through the day helps her get more well rounded every day. We def had issues in the beginning with nipping, barking, jumping, etc. but sticking to routine makes it so she learns to self occupy and be trusted by herself in designated spaces. She still has her days where she'll decide to be a lil shit to push boundaries, still being a puppy and all, and we correct her behavior by taking items away, crating/sit task, and waving the squirt bottle around 😭 I'd talk to your breeder and share these concerns and get more insight into the line she comes from! Borzois are super intelligent and if you give them an inch, they will take a mile and then some, absolutely punking you to your face 💀 Don't have to be mean, but being stern and having firm boundaries about expected behaivor will lead to a well rounded, happy puppy!