First, what is her overall & general heart condition? Does she feel difficulty breathing when running or going up stairs? Second, it seems that your daughter has already had the heart surgery when she was younger. What about her echo test results? At last, why would she exercise? To the best of my knowledge, there is no evidence that exericising would be do much good to tetralogy of fallot. I do not mean she has to sit there and not move. I just say if she exercises moderately, such as walking and jogging, that would be OK. Too much and vigorous exercising would make her heart overloaded.