well i'm only 9 but some advice is get an expery r someone experienced because otherwise you get problems like the saddle being to small/big so you could get a saddle fitter yes it's expensive but it works :D
if you know the size of your pony's saddle ATM then look at somwere wich sells new or good condition 2nd hand tack maybe sidney free or try gum tree :)
Darcy + Cartoon xxx