There's no doubt that having an older brother is one of the greatest gifts because of how caring, devoted, and protective they are of you (when they want to be). My mom always confesses to me how much my older brother loved me when I was born, and how excited he was to have a little sister. Yes, I had the constant teasing, but I wouldn't have had it any other way.
My brother, and I are separated by eight years which is just enough to not get on each others nerves while still being super close despite him moving away when I was only eleven. By having an older brother I will always have the support system that I need. Through high school especially my brother was a constant in helping me, and being their for me when I needed him.
When you give a girl an older brother you give her a lifelong best friend.
He will always be there for you, and never leave your side. He will always accept, and be happy when you have exciting news while supporting you through the bad times.
You give her immunity to a nasty smell
My brother played a lot of sports through high school, and always came home with the worst smell. Boys are just gross in general. He always thought it was funny to come up to me, and fart right in my face, but I still love him unconditionally.
You give her someone that will protect her
My brother always jokingly says that he will punch whoever breaks my heart, or when I was younger beat up the kids who teased me, but he would actually do it in a heartbeat. He wouldn't let anything happen to me to the best of his capabilities. It was like having a bodyguard that was just a phone call away.
I can tell you that my brother and I were not super close when I was younger, but as we've grown older I do consider him my best friend. I never realized till the last few years how important it is to have my brother in my life, and I wouldn't have had it any other way.