Maybe as an interim solution put her in a wondersuit with feet in it, use booties that tie on, or I saw really cute knee high socks in Big W the other day.

Then if it is behavioural maybe try distracting her every time she starts doing it.

This sounds a bit random I know but maybe a spray bottle with a bit of water in it and spray her feet every time she starts doing it. That means if there is some sort of irritation it will momentarily soothe it and will distract her from what she is doing.