I smile because you are my sister, I laugh because there is nothing you can do about it!

"Sisters are different. They heard the sobbing in the darkness.
They lived through all your triumphs, all your favorites,
all your loves and losses. They have no delusions.
They lived with you too long.
And so, when you achieve some victory, friends are delighted -
but sisters hold your hands in silence and shine with happiness.
For they know the cost."

"Having a sister is like having a best friend you can't get rid of. You know whatever you do, they'll still be there."
"A sister is someone who knows everything about you and loves you anyway."