Dear Vicki
As mentioned above, a 3 mm ventricular septal defect is small and what we call hemodynamically restrictive. This means that it does not cause any specific problems for the heart (unless it is a perimembranous defect, which can cause problems with the aortic valve). Therefore, we don't do anything for a defect of this size. Her other problems are likely unrelated to her heart, although without evaluating her, I cannot say for sure. I would make sure that, at minimum, she is adequately hydrated, as many children and adolescent patients do not drink adequate fluid, and can then have worsening problems with autonomic nervous system control of the blood vessels, etc.
A 3 mm VSD in a 6 year old would be very small, and is NOT causing the problems with blueness and body temperature/circulation issues. Some children have issues with this - my daughter is one. Her pediatrician just called it a primary vascular phenomenon (she mottles VERY easily, even on warm days and has Raynaud's Syndrome, and even on warm days her hands and feet can feel very cold, she's only 2). We were told that this "flukey circulation" can sometimes persist into teenagers.
That said, you might want to have her checked for thyroid problems, as they can cause problems with temperature regulation.