today is my friend's birthday,I'd like to take the chance to say happy birthday to her.Wish you are prettier. 这个是非常口语化的了,不要用什么字面翻译我的一个朋友,什么one of.. 就说是你朋友,然后借此机会用take the chance.因为opportunity太正式化了.
Today, is one of my friend's birthday, I would like to used this oppotunity to tell her: " happy birthday! I hope you grow to be prettier and prettier!"