Maybe it's because Mildred felt she could finally hang on to a human again - someone who would be there for her. Even if only to help her blow her nose.
It didn't take long for her to find the confidence she would need to be a cat again.
In fact, someone has already applied to adopt Mildred. To take her home and love her and maybe, once in a while, get sneezed all over.
Gesundheit, Mildred. Or, more appropriately, bless you. And the people who were there for you.