My husband and I have this really cool idea for when we get ready to tell our families that we're pregnant (which we're not right now). We're going to give them all a gift that "promotes" them to their new status. This one will be for both our baby sisters.
A sister is someone who is by your side no matter what. They forgive easy and don't let petty things ruin what is between them. You can be in a big fight one day and best friends again the next day. Sisters aren't for sometimes, sisters are forever.
My dad (only child) could not grasp how Mom, myself, and my 2 slightly younger sisters could be screaming & yelling at each other for 10 minutes, then 5 minutes later sitting at the kitchen table laughing & cutting up! (it had/has to do with getting it off your chest and not holding a grudge, my dad was very, very good at holding grudges!)