What is the probability of a 37 year old woman with normal blood pressure having a heart attack?

Possible: There would have to be a strong family history of same, high blood pressure, increased catecholamines as in adrenal tumors. Errors in cholesterol metabolism. As you can see it is complex. So if family history is benign it is unlikely.

Depends: On other risk factors. You do smoke which increases your risk. High cholesterol, diabetes, obesity, family history, certain illicit drug use can all contribute to heart disease. Eat a healthy diet, exercise, stop smoking and have other risk factors evaluated by your doctor to decrease your risk.