Variations are shown with parent Legenda theme, so it means they are not loading only with the child theme because of the customizations you made.
You have to check your own changes yourself as we don’t know what you edited in the code.
I’ve checked the product https://www.chuchick.com/shop/dotted-lace-dress/ and variations aren’t shown even with Twenty Fifteen theme. Please check yourself.
You have to ask Woocommerce support regarding this issue and mention to them that the problem persists with Twenty Fifteen theme too.