You can set your network router to assign each computer a different internal IP address i.e yours is 10.0.0.5 and hers is 10.0.0.4 each time instead of being random
Americans want 192.168.0.4 and say 192.168.0.5 because their networks are different to Australians but as long as each is fixed that is fine
Then for internet play (as apposed to internal networks) you can bridge each to a different location so Larian can tell them apart
Look up the book for your home router and it will have these settings or go talk to a local computer shop / ip provider about setting up a tunnel for best results
