SO insisted on the testing, not me, because she works around a lot of other people and children and did not know if she was contagious.

She also thought it would be helpful to know if exposure = any additional immunity down the road, since all of the facts constantly change

In our area, when kids test positive, they don't have to be tested for many weeks after. I know several that tested positive a few weeks before Omicron hit, then were refused when they eventually had Omicron symptoms.