To my sisser (yes, that's how we spell it to each other)

To my big little sister,

You and I, we couldn't be more different. We are almost 10 years apart, polar opposites in the attitude department, and couldn't be picked out as sisters in any line up.  Your childhood consisted of me making fun of you, ignoring you, or making you believe the most ridiculous things possible (for example,  botulism, or the cloud makers). We fought bitterly, never did anything together,  and avoided each other.

Now you're 20 years old,  and not much of that has changed,  except for the fact that I consider you one of my best friends. I still pick on you (its how I show my affection), I still try to make you believe everything i say (because you make it so easy), but I couldn't live without you. All your eccentricities,  your pets, your huge soft heart make you the best little sister I could have asked for.

Plus, you're totally weird, and I dig that.