What should three year olds sugar levels be?

Please tell us why you are asking? Does she have gestational diabetes and you have been asked to check her blood sugar level in the morning ?

Please tell us why you are asking? Does she have gestational diabetes and you have been asked to check her blood sugar level in the morning ?
I want to know what to look out for as she is being tested for diabetes

Please tell us why you are asking? Does she have gestational diabetes and you have been asked to check her blood sugar level in the morning ?
A 3 year old couldn't have gestational diabetes. That only happens during gestation, i.e. pregnancy.

Very young children can become Type 1 diabetics, although it is fairly rare. The average onset age is 13-14. Our son was 14, about puberty onset. Fasting blood sugar optimum is <110 mg/dl. Children never are Type 2.

A 3 year old couldn't have gestational diabetes. That only happens during gestation, i.e. pregnancy.
I think what I meant was being born with diabetes.

At a guess a kids level will be close to an adult level , though I did take a look.

The target range for young children is to achieve pre-meal sugars of 6 to 12 mmol/L (110 to 220 mg/dL). This range allows good blood glucose control while reducing the risk of severe hypoglycemia.

Note = My Grandmother and friend both have Full Diabetes ( No insulin production ). So I know about the levels. Also note I've given you a range due to other factors like weight , size etc , though your doctor can help with this.

Hope this helps.