You have become an amazing big sister. I will admit there is room for improvement in the little sister department (as will your older brother, I am sure). But I know being there in the middle is a tough spot to be. Regardless, you really do try and make the best of it and your love for your little sister is beyond compare. My heart melts when you worry about her safety or that she is becoming too independent. Which for those who know you, is completely and utterly ironic.
Happy 9th Birthday, Sweetie.