What is her height and weight? Is she overweight?
Get her Blood sugar levels checked (by a standard pathology lab) - Fasting and Post meal.
If the sugar levels are borderline, get her HbA1c
done which while show her average blood sugar level over last 3 months.
If at all the sugar levels are above the normal levels and there's is a doubt between Type 1 and Type 2, get the following tests done to get more clue:
or serun insulin
Anti insulin antibodies
Anti Islet cell antibodies
Type 1 needs insulin. Initial stages of Type 2 diabetes
respond to oral drugs.
Hope the blood tests turn out to be normal!