Happy birthday to my younger sister who a lot of people think is actually my elder sister!
I’m sure it’s only because you’re so wise and mature that people think you’re older than me anyway, sis! Either that or I just seem super young and immature!
You’re another year older and more beautiful than ever, little sister! Happy birthday to you!
Just a word of wisdom from your dear elder sister, keep hold of your beauty and cherish it for as long as you can because once you get to my age those good looks won’t stay around for long!
It must be so nice not ever having to worry about your age because at least you’ll always be younger than me! That’s possibly the best gift I could ever give to you!