IT's easy, I was doing this when I was a kid. (not buying seeds)

You place an order about half way through the billing cycle, when the statement comes you grab it. Eventually your parent realizes the bill didn't come and usually will call to make a payment over the phone. I've done that about 5 times in my life and never got caught. If she gets the statement, she'll probably review it and you'll be busted. I wouldn't risk it.

But you should just get some cash of your own and have an older friend let you use their debit card or something. Well, maybe if you steal they won't trust you with the debit card, but you can be there while they order it for you or something.