We just know each other as acquaintances

Hello AL!
A few weeks ago I sent a letter to a girl who is very paranoid about her grades. The essence of the letter was that she probably wouldn't be valedictorian (her dream), so she should just calm down about it. That's what I intended to convey, but apparently everyone else took it as me insulting her, not giving her frank advice. Now how exactly should I apologize? She and I were never really close, we just know each other as acquaintances. Any ideas for making an impression that I am sincerely apologizing? I really am sorry for bothering her.
-- Impulsive

Yo, Impulsive!
I can understand if she asked for your opinion, but you went out of your way to write this to a stranger. You're a FREAK! Keep your nose out of other peoples business and they'll stop thinking of you as an asshole with alot of time on your hands.

To apologize, tell her you're sorry for buttin' in, but not with another letter. Grab your balls, or your couch, and talk to her face to face!