As someone who's had a little sister for over two decades so far, I can definitively say that it is a great thing. More than great, in fact. It is excellent. (Shout out to brothers! I have one of those, too, and I will write an article about how much fun that is at another juncture.)
A sister is a unique person in your life — in so many ways she is more than your best friend. She's your sister! Get it? It's another level of friendship and trust and allegiance entirely.
So this is for all the siblings out there who relate to having and being a sister. I'm sure yours are great. Mine is the best, though. But yours are cool, too.
These are the greatest things about being best buds with your sister.