And I believe you made a very good guess.
Power outages can wreak havoc on a computer system logically (software logic that is) as physically (mechanically). As a result, it would not be surprising that certain settings on any router or computer for services such as Internet or network access protocols could be impacted as well.
So it is a matter of looking further into your firewall settings, and learn how to enable, disable and create rules within the firewall, so different ports can either allow or block certain traffic in your network with that firewall.
• So in the case of your iPad, it appears that somehow the firewall after the outage must have gotten confused and more than likely blocked the hardware address (also known as a MAC Address
-which is the unique indentifer number the each component has that is recognized by the network those components are in) of your iPad, but permitted the access of the hardware address of your Netbook and your girlfriend's iPad.
This is the best assessment I can make from a 3rd person, technical perspective.
I hope this helps.
Very glad to read you are back online now.
Thanks for allowing me to assist you.