Age of characters in the show

I was just wondering is Mehar older than Bittu and Rana or are they older than her. I can't seem to find anywhere where they tell you who the older sibling is and who the younger sibling is. Is Mehar the youngest sibling or are her two stupid brothers younger then her? 

As far as I can reconstruct, Mehar is nr 2 (after the eldest brother), then comes Bittoo, and Rana is the youngest.

But one would need to watch all episodes right from the start to get this confirmed 😃