She's 15 years old and 5ft 7, but she might grow a bit more. She's had this heavier than a blacksmith's anvil mountain bike for years, it's served its purpose of getting her used to bikes, and also building up strength due to the fact that a lot is required to peddle the very heavy object! We went out yesterday for a few miles and god was she struggling to keep up, even though i was only cycling at a slow to medium pace, and those hills must be a nightmare as the gears are sticking and those near motorbike tyres don't help! Time for summat better was my thought, so i'm wondering if it'd be better to go straight to a decent lightish road bike, complete with spds or make the move gradual and maybe buy a hybrid or a second hand tourer maybe? She's never tried spd peddles, infact not even clips, just basic peddles. Though if she ends up with clip in peddles she'll probably fall off and as she's pointed out, she'll have to wear the same shoes all the time. What do you suggest, i don't want to spend a lot of money on something she might grow out of, or put to one side for the winter months. New road bike, decent second hand roadbike, or a better mountain bike maybe? Should i buy an expensive one that'll last for years, or a middle range one that'll do the job without having to use it all the time to justify the expense?