Child Page ordering is used in your product group pages Sort Order is used to control the order in which your items are presented. display order of any child pages listed under the Parent group. For this example the parent group is the "Shop" page.
To edit the page sort order, navigate to the Pages section Parent page and click Edit (1) and select the Child Page Sort Order from the drop-down (2)
Select the desired sort order from the dropdown, and then click on Save Page to continue.