TL;DR: My mother went in for her appointment today and according to her doctor, her immune system is dangerously weak. Weak enough that she has to wear a mask when she goes anywhere (and so do the rest of us) to avoid ending up in the ER.

Her immune system was weaker than most people's for decades, we just accepted it. But now its something we need to be very much aware of when it comes to planning trips for necessities. Because she was told that if her immune level is currently at 0.9 (I think) and if it drops below 0.5, she's in trouble.