A UGreen DXP8800 will be used as an online file system. This will have its own domain that would point to the NAS. Every pool of drives will have its own subdomain, so for example, my pool will be https://frank.fsp.wtf. The child will be able to upload files to their online files site, and provide a share link with anyone they want to send the link to. Going to the subdomain directly will redirect the visitor to the appropriate domain. Therefore, if I wanted to share 20260409-2120.png to someone, then the web address will be https://frank.fsp.wtf/photos/20260409-2120.png as the address. If I no longer wish to show the file off, then I will simply delete the file from the online files server.
When the child leaves my care, they will lose the access to the online files. Their subdomain will be deleted, and the drive pool they were using will be formatted for the next foster child.