The criteria for a blue badge, she must be in receipt of the highest rate of mobility, which means she cannot walk unaided for more than 50 metres at a time, which is I believe is 5 lengths of a red bus. Not 20 minutes at a time and without frame or walking stick. It will make a mockery of the system if she can get a badge.
Even with the medical evidence, she will have to show how her feet affect her day to day life.
There is documented evidence online of her walking around looking absolutely fine, in no pain whatsoever and walking upstairs, normal pace, without holding on to the railings.
I’m with with dc16, just when I think she can’t wind me up more, she pulls it out of the bag.