If she is "older" or has underlying health issues, this stuff can make you seriously ill. She needs to seek medical attention and not sit around waiting for some "supplement."
Several of the OTC anti-viral supplements, including quercetin (which she had), are likely effective prevention and early treatment for most people. But she was rightly concerned about her blood disorder, as it is known that the virus can impact hemoglobin metabolism and do substantial damage even in a person without thalassemia. I pray it’s not the case, but she could have deteriorated rapidly into ICU territory.