Here's a link to hyperglycemia (high blood sugar) it does say it can be caused by excitement, but since she is still not herself you need to find out the underlying cause. High blood sugar is very damaging to internal organs. I think she needs more tests to rule out other causes if they know for sure it's not diabetes.
It mentions cushing's disease - I lost Lacy due to this and it is usually diagnosed in a pet 10 years of age. Lacy's first symptoms were eating, eating, and eating, like she was starving. She went from 4 to just under 7 pounds in a couple of months. I don't see this being the cause.
By any chance do you feed Royal Canin?
http://consumer.vetmedcenter.com/Con...cemiaFK1XX.xml