Ok...A couple things... Is your mom assuming her flat tire is caused by you doing what you did with your friend in the driveway? That is if she is aware of it.? If so, I can almost guarantee you, if I was your age, I would be getting the EXACT same punishment, and probly more. Would be my fault because I did not clean up my mess throroughly enough to prevent such accidents.
Even if it is a nail from the road, and she knows of your crap in the driveway, she can still put all the blame on you...It's what parents do, You can't argue with em.
ALSO, If its a small leak/whole, Go down to your local auto parts store and buy, Fix a Flat....Its a liquid in a can that you put in through the valve stem, Just like you would puttting air in your tire...Doesnt get much easier than that.
Anyhow, Good Luck.