Because they found the Philosopher's StoneThere is no other explanation.
Ads and media inserts have alerted us to another generational jump in the storyline of Kyunki Saas Bhi Kabhi Bahu Thi, which as per my rough calculations, makes the time period somewhere in 2130. This is the greatest giant leap in the telling of futuristic science-fiction ever since Douglas Adams ordered one whisky too many in Innsbruck.
But what infuriates Shahnaz Hussain and co. is how Tulsi and gang manage to remain so ageless, fresh and crease-less (both sari and skin)? The only explanation is that Ekta Kapoor ("Eeektaaa Kaporr" today?) has found what has eluded even Lord Voldemort i.e. the Philosopher's Stone.
Move over J.K.Rowling - it's time for Tulsi and the BaSilly