Hello and thank you for using HCM. I carefully read your question and i understand your concern.But don't worry. I will try to explain you something.
My opinion is that this sharp head and chest pains should not be related with heart problems. Usually ischemic heart pains that may lead to
heart attack have some characteristics. They are usually retro-sternal pains like tightness or heaviness. They may radiate to one ore both arms,neck or jaw.
Typical angina or ischemic heart pains continue 10 to 20 minutes. In heart attach the pain is very heard and continues for more than 30 minutes. It may be followed by dispnea,
nausea and sweat.
My opinion as cardiologist is that this sharp, short pains through head and chest are not typical heart pains. They might be just nervous system pains.
I don't know your sisters age, but if this pains persist and if she have ischemic risk factors like :
smoking,
hypertension,
diabetes, dislipydemias or heredity factors that she should make a simple chek up with an electrocardiogram, echo-cardiography, a blood analyses and maybe a
stress test if your cardiologist agrees.
So don't worry and if this episodes persist she may do this simple thinks.
Hope I was helpful.
Best regards.