You don't know it is anxiety, GERD or esophageal spasms, costochondritis, or heart pain when someone comes in complaining of chest pain. That's why you need to get physicians to properly evaluate her.
If the doctor doesn't determine the cause is musculoskeletal in nature (like the pin-pointed pain of costochondritis they can discover with palpation) causing these chest pains, a proper work-up including EKG & blood tests to rule out heart attack is in order... and a nuclear medicine stress test if those come out okay to try to see if she is having angina due to a blockage.
You mention she has heart murmur and aortic stenosis. When was the last time she had an echocardiogram to check on the murmur to see if it is any worse than the last time? The fact she has aortic stenosis (narrowing) is a big reason to take her complaint of chest pain very seriously. Please, you don't want to limit it to taking her blood pressure, her heart rate or her oxygen level in her finger.
If all heart tests come back normal, is she taking GERD medication? If she is, a GI specialist should be consulted to try to determine if she needs to change medications or why she is still have GERD symptoms that are giving her pain, if it is GERD causing it.
Please see this journal post I did some time back:
http://www.medhelp.org/user_journals/show/315540/To-all-the-medical-doctors-who-might-read-this