A friend of a friend died yesterday, she was in her 2nd trimester of pregnancy and out of nowhere she died. She said she had a sore throat and went home to take a nap, what could have caused her death?

any number of things from heart attack to some underlying disease process no one was aware of. Only way to know will be through the autopsy results

Heart attack.

With that little information it is really hard to tell. She may have had some underlying health issues that u know nothing about, heart problems, high blood pressure, the placenta could hav pulled away from the uterus & caused internal bleeding, she may have had a stroke, a blood clot that broke loose, she may have contracted meningitis, there r so many reasons people die suddenly that unless u know their specific health or any issues with it, it is hard to tell. Her sore throat may or may not have been part of the problem. l certainly send my sincerest condolences to ur friends family & hope they have the faith & strength to get them through this horrible loss of two people.

Sorry to hear about that. That is really sad. It could be so many things. She may have had an underlying infection, threw a clot, stroke, heart attack.