Is Calcification In The Area Where Ribs Meet The Sternum In A Teenager A Cause For Concern?

My daughter just turned 18. She has always been a superb athlete. However, since middle school she seemed to lose much of her energy and speed. For about two years, she has been complaining of chest pain. About a year ago, she had an echo which showed some regurgitation and the slightest of mitral prolapses. Her cardiologists have assured us that her chest pain is not related to her heart and she was given the okay to return to varsity soccer. One cardiologist suggested that the chest pain could be anxiety related. Recently I changed her primary care provider. I showed her a recent video I had of the tail end of an chest pain my daughter was experiencing. The doctor seemed very concerned and ordered chest and rib x-rays.The x-rays revealed calcification where her ribs meet the sternum. Also, the doctor did an in-office test of my daughter s lung function, where she had to blow really hard to quench the flames . She tried several times but could not quench the flames. The doctor is now checking her renal function and thyroid and parathyroid function. I am very concerned that these findings point to a malignancy or some kind of systemic disease. Please help me understand what is going on here. Thank you.