I guess it just depends on the feet size really. My son is almost 3 and he's got small feet. my daughter has bigger feet and a little chubbier too. All on judgement call I guess. If you don't choose to bid sorry they didn't work for ya.
My daughter is tall and petite, but she's nearly a size six shoe now. She has long and narrow feet. Wish she fit it. Good luck with your auction though :)