I'm officially at a loss.  Have tried different saddles, different pads and today tried the Total Saddle Fit (shoulder relief) cinch and that was probably worse yet.

We're talking about a 11.3 pony, so my options for saddle and pad are slightly limited.  Heck the TSF cinch needed a converter because they dont make a small enough western cinch.

She is built down hill but only by maybe an inch and she carries her head at wither level. Shes also big booty and narrow shouldered.  The saddle ALWAYS slides forward, trail riding is a b*tch with any hills. Only thing that has saved my daughter from going over her head is the back cinch. And she's got cinch gals more times then I care to count.

She is currently rode in a 13" Marth Josey, a 1 1/2" felt pad and a cheap (all the pony stuff is cheap made) neoprene girth.  We've tried Corriente and Teskey, built up pads and thin pads, wedges, no slip pads, string girths and neoprene (again options are limited with a pony).

I'm wondering if crupper/breeching will be our only way to prevent this but that means atlerations to the saddle.  The saddle slips during arena work as well. Guess we can start a new trend of barrel racing in breeching?! 

Suggetions?!

And since I'm biased and think they are the cutest team ever, below is the pony of topic.

I had a gelding with basically no withers and had this problem. I used a memory foam pad at the front and it really worked. You may have to trim it up for the pony because the one I had was horse sized. It basically looks like an upside down V and is probably 10" by 10" or so and sits right over their withers. Good luck, and yes yes yes they are such a cute pair! 

A crupper may be the way to go.

but check out the “Performance Pony Company” - they do quality made pony tack, a friend of ours owns them.

I think an 1-1/2" pad ( If I read that correctly) is to thick. For blueberry , and such small rider I would guess a 1/2" five star/wool pad would work wonders. 

Are you sure the Martha Josey is not a wide? And why such a thick pad, is it to get the saddle to fit better maybe? Do you have any pictures of the pony saddled up just standing still so we can have a look. 

Just wanted to add, A youth Bob Marshall would probably be a better fit.  

My options are limited with the pony for quality and size.

Here is the pad she is currently using, it might only be an 3/4" or an inch

I dont currently have a standing pic good enough to show saddle fit but I do have one with the saddle sweat marks, she never has dry spots.  

There are those non slip saddle pads to. Reinsman makes a " Tacky too" pad. Might be worth a try.