1. Ayan was shocked to see zoya in the 1st epi, ever since they haven't faced each other.
2. There is a connect of Zoya with Gudiya factory ka raaz
Therefore, my conclusion is, Zoya's double role as her mother... we hv seen many serials where mother and daughter are look alikes, i.e. Zoya's duplicate (her mom) was the lady who was killed by Raziya in Gudiya factory. Zoya's duplicate (her mom) maybe Mamujan's first wife, i.e Raziya's Sautan, thats y Raziya kills that lady & even Mamujan doesn't know about this murder.
Hence, Zoya maybe Mamujan's daughter from his first wife i.e. Zoya's duplicate (her mom).
P.S. Ayan might have seen Zoya's duplicate (her mom) in Mamujan's photo album.