Your sister is always the first female friend you will have in your life. Nobody will ever be able to understand your craziness like your sister and although you don't see each other as much as you'd like, she will always remain your friend and be there for you when you need her the most. While people will come and go in your life, your sister will be in your heart for a lifetime. If you have a sister that you love with all your heart..
If you don’t understand how a woman could both love her sister dearly and want to wring her neck at the same time, then you were probably an only child. ~Linda Sunshine
Sister. She is your mirror, shining back at you with a world of possibilities. She is your witness, who sees you at your worst and best, and loves you anyway. She is your partner in crime, your midnight companion, someone who knows when you are smiling, even in the dark. She is your teacher, your defense attorney, your personal press agent, even your shrink. Some days, she's the reason you wish you were an only child.
-Barbara Alpert
Sister is probably the most competitive relationship within the family, but once the sisters are grown, it becomes the strongest relationship.
Margaret Mead
For there is no friend like a sister in calm or stormy weather; To cheer one on the tedious way, to fetch one if one goes astray, to lift one if one totters down, to strengthen whilst one stands.
Christina Rossetti