Why does Sara use the surname 'Ali Khan' instead of 'Sultan' in Bollywood?

Sara Ali Khan is one of the most recognisable star kids in the industry currently. Since her debut in Kedarnath and appearance on Koffee With Karan with her father Saif Ali Khan, she's been followed by the masses.

The actress, during a video called EIC vs Bollywood revealed that her last name was Sultan. I'm not sure how it's Sultan but even some older articles on her refer to her as Sara Sultan. This could either be because of her Pataudi heritage and the titles that come with it or her maternal side. Amrita Singh's mother's name was Rukhsana Sultana so Sara could have taken the surname from there.

By taking up the name Sara Ali Khan for professional spaces, is it to establish that she comes from a filmy family?