Supernumerary digits are not rare, but these are particularly well formed and appear fully functional - not like the vestigial stumps that typically have to be amputated as a nuisance.
I like the fact that the report at the Chinese link describes her as a "special girl." In many cultures physical variations are celebrated rather than decried.
One wonders what the future will hold for her. Will the extra digits give her enhanced capacities as a baseball pitcher? magician? pianist? guitar/banjo player? The mind reels...