I agree with you Zoelula. My daughter was recently dianosed with type one and that's what would happen to her too. Although mood swings and headaches have been associated with my daughter's highs and lows, I think that your daughter might be suffering from migraines or allergy related headaches. Irregardless, anything having to do with the symptoms you described should be looked into in order to rule in or out any possible adverse causes. Hope I helped a little. God bless you!
A reading of 111 a couple hours after a milkshake is totally normal. I'm a type 1 diabetic and if I drank a milkshake I'd likely bee 250-300!
Her symptoms don't sound particularly like diabetes. More common symptoms for diabetes are increased thirst, increased urination, sometimes increased hunger and weight loss as well as low energy. My suggestion would be to take your daughter to her pediatrician to be checked and share these symptoms with him.