I thought it was a really good rant. Everyone recognizes the frustration that social loafing brings to a workplace environment. I would have kicked her out the moment she left early- and I would have given her a warning the moment she waked in late. That's ridiculous! Hope your boss tightens up the policy a little, so you don't have to deal with that again.
I'd give it a 9. It was coherent and used proper spelling/punctuation. Which is more than I can say for a growing number of posts, lately.
Did this lady come from farther up canyon?
Hard times make strong men
Strong men create good times
Good times create weak men
Weak men create hard times