Ride On Lone Ranger....actually WAIT!

So yesterday my dad invited the girls and I over because he knew that when my husband would get home from working he would need to sleep so we went over and played. It was such a nice day. M asked grandpa for a tractor ride...which she does almost everytime, but grandpa tried to convince her otherwise. It's so funny when I can tell she is really putting those puppy dog eyes to work. Still he resisted her powers, but oddly he walked up to the shed. He comes back with the lawn mower and M asked what he was doing. I told her that maybe he was going to give her a ride. He pulled up and told her to get on and then he got the mower going and let her drive it ON HER OWN! I hope you can sense the screaming that was going on in my head at this point....WHAT ARE YOU CRAZY?? She was going slow, but still I'm thinking she's going to run into a tree or something and hurt herself and destroy the mower at the same time. She did real well. Then she decided she was going to cross the driveway and started heading to the barn bridge. My dad and I are watching her and I said I hope she doesn't think she's going to go up the hill, because either she's going to drive right into the barn or go off the side of the hill. My dad just looks at me and says "Nah" and then a few seconds go by as we watch and her direction doesn't change and he says "well maybe..." It looks like if she goes up any further she will go off the edge if she doesn't pay attention so I'm screaming and my dad is screaming which she doesn't hear and then we starting running to catch up with her and as soon as I caught up with her she just turns it around and comes back down the hill and just smiles at me and waves since she didn't know why I was running after her to begin with. So for at least 5 or 8 more times that she went to the hill I walked right by her to make sure she would just make a loop and come back. My dad was as calm as can be so am I just too paranoid? do I not trust my 6 year old on a lawn mower? !! (absolutely not!) She drove for about an hour and in the last ten minutes by dad directs her around the house and to the field and then M speeds it up and is going too fast for my thoughts and I'm thinking oh she really is going to hit something, but no she didn't. In fact grandpa had taught her how to slow it down and so after a few minutes she slowed it down a bit. Then I thought it was time to go home. It was so nervewrecking yet I was proud of her...... but I am thinking I am not going to let her do it again anytime soon! (How will I survive years 15 and 16??)