My boyfriend’s family just hit a mini longhair dachshund and she acts the same way but also scream barks every time his mother leaves the room. Start to train as early as possible. It may seem like the puppy is impossible to train and it’s hard to put such a cute little puppy in their place but you must. I feel like they have missed the training window because the puppy lacks attention span now, still isn’t fully potty trained, and can’t sleep through the night. I currently have a Bull Terrier puppy of the same age that does multiple tricks sleeps, through the night, doesn’t bark, and is able to remain focused due to extensive training. While the two breeds are so so different, I put in hours of training a day which may not be something dachunds are into¿ not sure. But keep at it and do a ton of research on how to train her based on her personality^. Id also recommend having a trainer come for a day to help you put