Don't they in any blood relation, they are beautiful, smart, ambitious.
Where are Ashima's parents? In London? They originate somewhere in the neighborhood near the city from which is Shiv. The children are probably born in the same hospital and is Ashima's mother Shiv's. She suddenly lost her baby or have it planted that dead girl as Ira was born. After she gave birth Ashima and the fate brought them together in friendship. 👏
Maybe?