this is a thyroid forum -- but your daughter needs an ultrasound of the heart (echocardiogram) to classify the murmur and it's severity.
Hi Charley
I was born with a heart murmur and am now 48 years old.
Get it checked every year by a Cardiologist to make sure its an 'innocent' murmur and she will be fine.
The usual proceddure though with people who have heart murmurs is that they must take antibiotic treatment an hour before having dental treatment.
It is simply a precaution to stop any bug going to the heart.
I have done this for years and no problems.
Your daughter may have an 'irregular' heartbeat which sometimes skips a bit (palpatation).
Again nothing to worry about as long as she has yearly regular checkups....she will live a normal life and give her parents the same headaches as other teenagers do lol.
Take Care
Debbie :)
(48 yr old woman with 3 kids)