Looking for a saddle for my 6 (rising 7) year old son, pony is 12.2, we don't have a saddler with a large selection to try from, would a 15.5" be too big??
How long is a piece of string? If you don't even know how to measure length, then how on earth do you plan to check the fit? Get a saddler out. Even if they don't have one to fit, they can tell you what size & fit to look for then come back when you've bought one to do any adjustments & check the fit.