Lakshmi and Meena's are Rohan's wives. Shalini is Meena's step-daughter.
How is Lakshmi related to Shalini ?

Answer: C. Mother

Shalini is Meena's step-daughter means Shalini is the daughter of the other wife of Rohan.
So, Shalini is the daughter of Lakshmi or Lakshmi is the mother of Shalini.