Sara has 2 movies in hand:
Coolie No. 1: a movie where the focus would totally be on the hero.
Imtiaz Ali next: well let's just hope Imtiaz gets back to his senses.
And Jahnvi has 3 movies:
Rooh Afza: due to the lead not being a star, Jahnvi will get a good role.
Gunjan Saxena biopic: where she has the lead role and chance to show acting chops.
Takht: a small role but the movie is huge.
So I think Jahnvi is doing much better and given thay she has Karan's support, I think she will emerge more successful than Sara.