Heart murmur is still there and it hurts when she plays basketball and sometime when she is doing anything.
It sounds like you have several concerns here: 1) your teenage daughter has chest pain and fatigue (but you don't say if the chest pain is activity related or not), 2) she has a history of prematurity and a heart murmur (not sure if the murmur is still present, and not sure what evaluation she had by the cardiologist 3 years ago), and 3) there is a family history of heart attacks and strokes in adult members of the family. The first 2 parts of your comment cannot be addressed without more information. The last part suggests that all members of your family should have their cholesterol levels checked, and avoid overweight and smoking. It sounds like you should start with an evaluation by your primary doctor as to why she is fatigued. She should have an electrocardiogram (ECG) as part of her chest pain evaluation (and perhaps a chest x-ray if she is fatigued) and then you and your doctor can decide if she needs to go back to see a cardiologist based upon the type and timing of her chest pain, and what studies were performed in the past.