all due respect jimmy, ( and I do have rspect for anyone who drives those roads to appleby) but I have to disagree a bit. ( I bet you thought I would!) as you say, you have broken horse to drive for many years, so you know whats waht and can react quickly and efficiently in a hurry, but this girl and her father havent, all of the equipment is going to be different for them, so I think its better to go slowly; lets face it , if things go tits- up in a cart, it can be much more complicated than ridden. If the pony has done all the longreining then you could probably do it a bit quicker, ( always have two of you when you are doing any of this) but I would still break it into stages, so before putting into a cart, get her to pull a small car wheel tied to long traces with baling twine that you can cut quickly if she panics. Get her pulling it over lots of different surfaces so that she gets used to different noises behind her, and over some uneven ground; do it all gradually, so as not to spook her. When she is doing that without hitch, rig up a sledge type affair using 2 poles (shafts) tied to a small builders pallet. It will look a bit like the things the indians used to pull behind thier ponys- can't think of the name at the minute. I have mixed views about tying clothes at the end of the shafts; I know someone who does that, but the downside is that if you need to unhitch the pony quickly, its harder and takes more time to get the shafts out of the tug- stops. But jimmy is right that you don't want the ends of the shafts near the ponies head ( I know someone once, who found they were attatched to a cart being pulled by a horse with no bridle where they had got the shaft caught in the throatlash- scary!!) the throatlash on harness is generally fastened tighter on a harness bridle so this doesnt happen. So I would say with the pallet training method which I am going to tell you about, make sure the "shafts" are only about six inches through the tugstops. The "shafts"ends on the pallet will be at a higher angle than whenyou are in a well balanced cart. Have someone at the ponies head they can help the pony turn left or right which is when the shafts will come into contact witht he ponies side. Sometimes they don't like that so have someone to help her get used to it. And they and you can keep watch that the "shafts" are staying in position. Fasten the pallet to the traces with baling twine to a swingle tree if you are using a breast collar on your pony; you don't want to rub her chest sore. And again the twine can be cut if you need to get her out of the pallet in a hurry. And then after she has pulled that for a week or two I would then put her in a cart. I am not trying to scare you, but please remember that if the horse gets spooked or bolts in a cart, the cart can turn over and that will really cause a problem as it starts going all over the place and turning up behind the horse, especially if you have been thrown out so its not got too much weight to stabilize it. This is the reason I always say take it slow and steady, and then you are learning at the same time as the horse, and are both better prepared if something does go wrong. I would also say always have someone with you so that in a problem situation the person can go to the horses head, and the other person is still in the cart handling the reins, and mostly, remember that all of this is fun to do, just think ahead and try to keep it as safe as possible. Good luck, and want to hear how you get on please?