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:

C-peptide or serun insulin levels
GAD-65 antibodies
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!

Regards.

Usually If its random blood sugar test A glucose level greater than 200 mg/dL may indicate diabetes, especially if the test is repeated at a later time and shows similar results. Your child has 160 which if taken as random blood test is not a diagnosis for diabetes . The standard diagnosis of diabetes is made when two separate blood tests show that your fasting blood glucose level is greater than or equal to 126 mg/dL. But the important point is as you are diabetic its important that you take care of your children as they are highly prone to diabetes and keep them healthy with nutritious food and physically fit.

You must have tested her with a glucometer for her capillary blood glucose. this will not be so reliable, and diagnosis of DM is not made without 2 fasting blood showing more than 126mg%.
you have been diagnosed at the age of 40yrs. Dont become too paranoid about the sugar levels in your child and subject her to repeated pricks. The best you can do is take a fasting random venous blood sample and then decide.
Meanwhile, try to go in for lifestyle changes in your family, changing the food habits and cutting down on junk food and also, increasing the physical activity.
The most important thing now is to keep your childs weight optimal as that would be the biggest risk factor