I would suggest you consider having your vet check out her larynx and her vocal chords.
You can read about a problem called laryngeal paralysis here
http://www.marvistavet.com/html/laryngeal_paralysis.html
it can go along with a low thyroid issue which is seen in this breed. Your vet can check for that with a blood test.
Sometimes the vocal cords can get a polyp or growth on them that needs to be removed and there have been cases were a weed seed has gotten caught in that area causing rough breathing etc.
So a vet visit is your best option to determine just what is wrong and how best to treat it before her breathing issues get worse.
Hope this helps you!
Dog Expert:Rescue, Train,Breed,Care
30+ yrs dog home vet care & nursing, rescue, behavior&training, responsible show breeding, genetics