Good Morning and welcome. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
The first thing to do is to have your vet examine Flossie since this may be due to a medical condition especially if she is not spayed. Other metabolic problems can cause this hyper behavior that can be treated with medication.
If this is ruled out, then I strongly recommend that you seek the aid of a veterinary behaviorist which you can find using this LINK.
There are calming agents such as a DAP Collar that decreases anxiety of this is causing this aggression or Rescue Remedy that also decreases anxiety. Both can be purchased at the pet store.
Your vet has medication that can help you train Flossie out of this hyper behavior by establishing yourself as the "Alpha Dog" and obedience training so she obeys you when you say NO!
You do have options and after speaking to your vet, they will be able to direct you so that Flossie stops this hyper behavior. Obedience training is essential.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, Dr. Loretta