somebody's being naughty

A few minutes ago, Anne snuck to the stairs with a pen and the library card I gave her. I told her, "don't be naughty over there." A minute later she says in a little voice, "somebody's being naughty." I didn't reply. Then she said a little louder, "somebody's being naughty." I said, "are YOU being naughty?" "Yes," she replied. She was coloring on her library card. I was just glad she wasn't coloring on the wall.