6. You can be incredibly mean one minute and best friends the next.
She’s your best friend and your worst critic. The anger between you flairs up before dinner and ends in laughter as you do the dishes.

7. You can show up at her house announced and stay for a week.
Another great thing about the sister bond is that her place is your second home. You keep clothes and toiletries there, you know your way around the kitchen and you have your own key.