With regard to Kathryn, the literature seems to favor leaving some contrast in the subject but allowing a zero-contrast background. Having some facial features at a higher contrast seems to be OK but perhaps a little too much in this case.
Some examples of wimmin here:
https://expertphotography.com/high-key-photography/
I've never done high-key stuff but my inclination initially would be to select the subject(s) and play with the histogram in Levels, then invert the selection and mess with the background to taste ...