Voodle wrote: If you're setting up a whitelist and only want it to apply to a single PC, you need to appy it using filter rules - that's under Firewall - Filter Setup - #2 Default Data set, on there you need to go into the first un-used rule (#2 usually) - just enable the rule, give it a suitable comment, set the Source IP to your daughter's PC (by clicking Edit, select Single Address) - leave the action as Pass Immediately and select the URL content filter you've made if that's how you're setting it up.
That should then just apply to the one PC.