Hi. To opine on possible reasons for the pain more information is needed. How old is your sister? Is this pain brought in by exertion. Since she has feet pain also along with pain in chest and arm unlikely that it is cardiac. But she needs proper evaluation with some basic tests like ECG to be sure
Next Steps
Consult a doctor for detailed history and evaluation. you can consult a Physician first and if deemed necessary the Phsyician will rfer you to the Cardiologist
Health Tips
such aches and pains, numbness could be due to
vitamin D or
B12 deficiency. You could get that checked after consulting a doctor