Crawford Custom Leather on Facebook as made me several sets for my own horses and for my neice and god daughters ponies, always does a great job and can make any size you need.
I got my son a breast collar from http://www.runninghardproducts.com/Nylon-Breastcollar-Custom-Color-... and it turned out really nice. I've also had a friend get her daughter a showman pony set w rainbow fringe that was really cute. All the custom tack makers will make pony size too, they will be more expensive but better quality.
I ordered a matching bridle and breast collar from Allen's Pony Express - they specialize in pony and miniature tack. My daughter had a bunch of swardski (sp?) crystals on hand and put them on to deck the whole set out. Later she added a wither strap to match. My granddaughter is pretty proud of it.
Thank you everyone!!! I think a little fringe set would be adorable on her little pony.. I coult pull it off but of course an adorable little child could right?!
KB Creations makes some super cute pony tack! Also I bought my daughter a showman fringe set and it has held up really well. I plan on replacing all of the conchos and buckles because they are cheaper quality. Looks super cute on her pony though!