Measuring dee ring (fall down staples) to dee ring really has no
bearing on the width and I don't know why people do it.
The shape and style of the tree's head and the gullet plate as well
as the style, amount of wear, the depth and amount of flocking in
the panel can be so different from saddle to saddle and what might
measure at 10 inches in one style and be classed as wide might be
totally different in another style. Each saddler also has different
ideas of where the staples or dees should be. So even 2 saddles of
the same make and model can be different if made by different people.
It is more a matter of experience and judgement of eye to determine
the width IF it isn't marked on the saddle anywhere.
Oz
she got measured in a GFS fieldhouse narrow medium, ive seen on online but dont know if its a medium or what, heres waht it says - 17" seat, approx 8" d to d & approx 4" inside front of gullet
Forget the dee ring to dee ring (fall down staples) measurement, it won't help you. Is the saddle advertised near you?
If so, try to organise a fitting with a local saddler or a saddle fitter if you can, before you buy it. Buying a saddle that you think might fit can lead to problems as the shape of the head that can vary so much from saddle manufacturer to saddle manufacturer and what width fits it one make may not fit in another make.
Oz
Sorry just re read your post, if she's been measured in a GFS narrow/medium and you are not sure about the on advertised due to vague description they have given either email them for more definate sizing or avoid.
Have you not got any local saddleries that can bring some out to you?
If you can afford it, that is your best option, buying a saddle online or through ads in mags etc is a bit hit and miss, even if it does fit well it will possibly need adjustment to fit your horse as well as the saddle may not be as good as the seller says.
Don't mean to be an old grump and pessimist but I have seen so many customers at stables who have called me out because their saddle they bought and thought it fitted, didn't and was causing problems, just bear that in mind.
Oz
Best get back to the seller of your saddle and find out 100% what the width is before you decide then, if it isn't that old surely they must know what width it was when they bought it, personally I would give it a miss and keep looking locally, good luck in whatever you decide, Oz
Doesn't make a difference to what? Locally? I think Oz is saying that unless you can try the saddle ie buy one locally from someone prepsred to let you try it, you're taking a big ganble. I know lots o fpeople are very particular about getting the "right" colour saddle but if you are looking second hand it's hard enough to find one in many instances without stacking that against you as well. I agree with Oz that you're best off working with a fitter to find one - D ring measurements aren't that helpful even if you're experienced at fitting your own saddles, but if you're not, then it's a minefield.