Later, I looked out the window and saw this: Apparently Karl had been cultivating and Heidi got to ride. He said she had been singing away as they went around the garden.
She informed me that Daddy let her drive too. He had let her take the lines in front of him and go around with the harrows a couple of times. "They went when I said 'Giddy up' and when I said 'whoa' they stopped!"