If you give a girl a sister she's going to have a forever best friend. She will always have a playmate whenever she is bored, someone who will never say no to playing Barbies and Polly Pockets and once their a little older someone to go on unlimited shopping trips and coffee runs with. She will always have someone she knows she can count on, to be there for her in good times and in the bad.
Once you give a girl a sister there is bound to be some fighting and arguing because that's what sisters do, they fight about who took whos clothes and who gets to choose which movie they watch but that's alright because at the end of the day she knows she will never have to question her sister's feelings for her.
If you give a girl a little sister she is going to have unlimited access to the latest fashion, a.k.a her big sisters closet. Once she has access to the latest fashion trends she is going to want to go out and show off the newest trends she's wearing so you're going to have to take her out with all of your friends.
If you let her hang out with you and your friend's shes going to make your friends her new friends. Once she becomes friends with your friend's shes going to want to become a part of your friend group.
Now that she's apart of your friend group she's going to want to go out and party with you and your friends and if you let her party with you and her friends your going to have to protect her, from a lot. From boys at frat parties to girls trying to pick fights over the stupidest little things, I mean, after all, she's your little sister and the mear thought of harm heading her way pushes you into mama bear mode.
If you give a girl a little sister she's going to have a lifetime of laughter and memories to reminisce about for years to come. Stories dating back to when you two were only young kids to stories about college days together all the way to stories about being old ladies in the nursing home together and let's face it you know you two are going to reak havoc, because of that's what you two do and honestly that's ok.