A doctor wore 6 face masks at once while testing his oxygen levels, and found he could still breathe

[Hortensis]

9. So, she no doubt stays home to protect herself. Except for

election day if she can't vote remote, then guessing she'll do whatever works best for her.

Those who must go out all the time need to try to routinely protect themselves adequately, though.

This doctor probably used genuine surgical masks, the kind you can't make a candle flicker when trying to blow through. I double up the fake ones available these day, the pleated blue types that look like real surgical masks but aren't. But wearing two increases the number of layers, allows me to offset to cover lower under the jaw, and also makes them fit a bit tighter around my face.

I haven't tried six but will for fun, though our best protection since we're retired is the same as your MIL's.