Kids can have high blood sugars when sick, and these can then return to normal... however, the very fact that she had high sugars is not normal... and she may be at risk of type 1 developing soon. Please do check her sugars after a heavy meal and see how she is going. Kids can go from apparently fine, to very ill, very quickly in type 1.
Hope that your daughter doesn't have type 1, but the best you can do is watch closely and catch it early if it does develop. Sounds like your doctor is on the ball.
With all that you are seeing, I wouldn't mess with guessing- get her into the doctor. It sounds like she likely has type 1, and since you have a 4 year old with it already- I'm sure you know how important it is to make sure they are being monitored by a doctor. Let us know how your little one is doing!