I'm kind of in your neighborhood if you need any additional help-Cedar Rapids area.
Have you contacted her breeder? That really can be a big help if the breeder has a good knowledge of her bloodlines, health history of the parents and such.
I think part of this might be stress from the summer to fall change of the family. Many corgis don't do well to change and it may be her way of showing her displeasure.
Also, I will see if I can get any good recommendations for trainers in your area that might help. I have lots of friends out that way.
Cindy and the crew at Foggy Bottom
www.foggybottomusa.com