And similar to your daughter, I failed a driving test once by 1 question. It was for my regular license though.
My parents were for it from the beginning (at least on the surface), and they continue to help me pay for the many expenses with loans and such. They didn't put any restrictions on me or my bike choice. Not to say they don't care about me, they just put the choice in my hands. My restrictions were stamped in from the safety course, internet videos of people doing stupid things and getting hurt, and a little bit of common sense on the side.
When a friend heard I was getting a bike, he had to have one too! Our first outing, he gunned it into a corner and pulled through in the opposing lane. Then on a straight section he decided to show off (if you call flying in a straight line showing off), and blew past me, just as a cop pulled out and drove by us in the opposite direction. Memories of the terrified look on his face still make me laugh

So anyway, showing your kid stupidity and its (negative) outcomes will help keep them from being a victim of it.
And as already stated, if it's going to happen, it's going to happen. Be there when it does!