I altered my friend's paper before she had to hand it in. I hope she likes it.
Altered how?
I left a cute message to my friend
You may think that's sweet, but it's her school work. Your little message may get her a failing grade since the teacher won't know otherwise.
I just want her to know how much I love her.
That's very nice and all, but tell her face to face. You don't need to be changing her work to get a message across.