I am a 29 year old female, 5'4", 110 lbs. is 115 a normal blood glucose reading 3 hours after dinner or is that considered high (pre-diabetic)?

Likely normal: You have a normal BMI. A blood glucose under 140 two hrs after eating is still considered normal. A better assessment to see if you are pre-diabetic is to get a fasting glucose, triglycerides, HDL cholesterol level, and blood pressure. If you have any 3 of the following 5 criteria you are considered pre-diabetic: waist >35 in, fasting glucose >100, triglycerides >150, HDL <50, BP > 130/85