lol, i think all of us have been there.
i just bought a bike and there was nothing she could do,
im not sure what the laws are like in reguard to getting your licence in oz, but in nz its 15 to get your learners which lets you ride a 250cc bike.
funnily enough, my mum made me do my licence but said i couldnt have a bike
yeah right! needless to say i bought the quickest 250 i could find a nice little rgv250, which my mum was none to pleased about, but she was the first one to blag a ride when she saw it
all i can say is try and clock up the mile/hours on a bike... any bike before you get a licence, and ry and minimise any crashes you have.
good luck