When I was really young, I was the youngest.. then my dad took me and I was then an only child.. and now that I live with my mom.. I have a little step sister and it sucks... If you are an only child.. you do not want to be shoved into Siblinghood... they're your shadow.. they copy your slang, your music, your clothes.. your dislike for pork, even get their hair cut like you. You think it's sweet... but then you have no privacy.. they lurk at your doorway, waiting for you to go to sleep so they can kill you in your sleep and hope that your parents won't notice when they're wearing your clothes that are two sizes to big for them.
But on a lighter note
.. I love your sister, she is smart, and amazingly mature for her age, and she has the most beautiful hair I have ever seen, don't ever let her cut it.