Not quite sure to blame those shoes. Something smells very journalist ‘science’ about this.
Ah, but Mom got lots of pictures of herself published. Bet no mention of Dad means she’s single and available, now very publicly known.
That is certainly an odd sentence. I'm picturing a TV doctor like House looking at the girl's feet and suddenly exclaiming, "You were trying on shoes at that shop on Piccadilly Street, weren't you?"
The insoles of shoes are usually excellent growth areas for various fungus, molds, and bacteria. This is why shoe stores used to not allow shoes to be tried on without socks and most had socks you could use to try them on. Yeah, the store socks were not much better but again, way back when, many local stores would tell you to keep the store socks (they were cheap anyway).
One cut or sore on your foot is all it takes to get an infection or pass one on.
A self-induced, common sense, problem, not the shoe store.