Share 'Child's Cutback'

My daughter will be showing W/T acadamy this fall. Her instructer wants a 18in childs cutback for her since shes only 47 in tall :) Ive had a hard time finding one. I would prefer used to new. I know this is the wrong time of year to look for tack..LOL I do have till September. Also I hope everyones show season is going great! Thank you for any help! Michelle