Zen cart installation / maintenance / customisation / hosting
Supported Modules: Dutch language pack, Multi site, Dynamic Price Updater and more.
Not sure, but looks like a checkbox is used... Further not sure if the plugin works/recognizes checkboxes... May want to switch to a radio button or dropdown with an additional option of both items and an individual price for that mixture. That's also assuming that the plugin works with multiple attributes.
ZC Installation/Maintenance Support <- Site
Contribution for contributions welcome...
But when I change family size same time change to extra options attribute.