If the PC can connect to the internet but the browser can't, it suggests that something is specifically blocking Internet Explorer. The obvious candidate is the firewall software.
Without knowing which firewall your daughter is using, it's hard to give very detailed instructions. Basically, you need to look for something like 'Program controls' and then look to see which programs have permission to connect to the internet. You'll probably find that IE is blocked. The instructions to unblock it will probably be self-evident within the firewall. (If not, try right-clicking on the reference to IE, to see if there's a 'permit access' option. Alternatively, if there's a red cross next to IE, left-click on the cross and change it to a green tick. The latter instructions work with Zone Alarm).
If you can't work out how to get into the firewall settings, just try temporarily disabling the firewall temporarily. (Press Ctrl-Alt-Delete and enter the task manager. Click on the firewall program and select 'End task'). At least you'll then know whether the problem does lie with the firewall.
Chris