Haha, I remember the days when i was still dumb enough to lick the tip of my toes just for the lulz.
Anyway, i'll remove the anatomical_nonsense tag, seeing that this manner of posture is still possible to do (albeit perhaps with the help of one's hands for those having them) by many people.
Given that she'd have had a fair amount of time with nothing but her feet she'd probably have developed the flexibility and utility to use them like that.
Prince Randian, who was born with no limbs, was still able to roll, light, and smoke a cigarette with ease.