I think it was established fairly early in the show that Swati..that's the name of the character, btw...is mad about RK..so much so that she can't take her eyes off his billboards even while crossing the road.
So, imagine her state if she were to see him live right in front of her, attending her brother's engagement no less! In my opinion, her expressions and reactions are all what one expects in a girl her age.
The controversy concerning her was that her mom tried to pass her off as boy so that she would get more roles in films..the child went through an identity crisis till her estranged father put a stop to it and insisted that she be treated as a girl which she was. Looks like she has survived that experience pretty well.