Why no delete/edit function for wall posts?

Why can't I delete or edit posts on my kids' profiles? Esp. if I have just posted a note about what my kid is doing and I realize too late that I made a typo. Also, my mom (the grandma :)) tried to post something to my child's wall and accidently hit "enter" with your default message still in the typing area. I sure would like to delete that; it looks silly. It could occur (families being what they are sometimes) that someone would post something inappropriate on a child's wall and the parent/admin should have the ability to remove these things.