What happened to naina's mom?

So the show has come to an end. And we have also seen a leap at the end where naina is living with dadi and her son. But I don't seem to understand, what happened to her mother? Or his brother? Okay her brother doesn't deserve her, but what about her friend? I don't remember her name, zainab maybe? What happened to them? Am I missing out on something?

there were many loose ends and also a sad ending..but its over

she is living with his brother in austria as told before