That just doesn't make any scientific sense, whatsoever. Placebo effect?
I will not argue the science, because yeah, it seems questionable. Maybe the vaccine stimulated immune responses even though the disease should have already done that. She is a smart gal, honest, about as objective an observer as you'll ever meet. I'm glad it helped her, for whatever reasons. I haven't had covid that I know about, but my guess is that it could get a person's emotions a little stirred.