2nd player access

[jjgibbs38]

I recently bought a laptop for my wife so she could play with me. She sees me playing and really wants to try it out, which would be fun having a partner.

Question: I have a router at home, if we hook up both computer to play together is that going to present a problem? I know there is a 1 IP limit but I'm not sure if 2 computers off the same router constitutes 1 IP or 2.

Secondly if it is 1 IP what to I do so we can play together from that point?

Any info is greatly appreciated. Thanks