You may want to check again to see if she has updated her opinion about that, or is willing to give a more nuanced opinion. If not, (or if she is genuinely confused about antigen and antibody tests), you may want to discount her opinions.
Oh, and I’ve been tested. PCR, mid-turbinate and throat swab. Because my work asks/requires me to be tested if I have a headache, and the test is free.