Pony Club sounds a good idea to me. And riding schools which have holiday clubs or pony cub branches.
But how are you wording your ads?
I would say why you are looking for a rider.
And if the pony is safe for a child rider, I'd say that too.
Otherwise one might wonder why you need a rider? I've twice seen RS ponies brought to demos by skilled young (student age) riders who have been riding them because they are "naughty" - being used to passenger child riders and taking decisions for themselves.
I keep an eye on local share ads and they seem to fall into two categories.
Owners with good reason to share and an attractive horse to offer - who want a sharer to cover part of the cost or so their horse gets exercised while they are pregnant or at work.
And owners who want a sharer to train or improve their problematic horse. Or to exercise an elderly, semi-retired horse for which they themselves no longer have time.
This second group may attract some riders. But not me.
There are a lot of ads at the moment from people looking for a sharer. It could be that while the kids are in school and the weather still bad, supply outstrips demand. You have to compete with them. And to word your ad so that it is attractive to the type of rider whom you'd like to have?
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