With only a few cows 'under her girth' I'd say she's doing exceptionally well! You can tell at certain points when she realized what she's supposed to be doing and starts following the cow on her own. As she gets more experience, you'll find that happpening more and more. She doesn't do it so much with the mechanical cow, but maybe she just isn't one to be fooled into thinking that a tarp is half as exciting as the real thing ;)