Sorry, just read your 2nd message (the one before my last message) and i do play Minecraft a lot, so I can understand, ironically, me and my friend love Minecraft but she can only play on the computer every other Saturday and Sunday (Custody issue) but we both have iPad 2's and internet at either house, and so stumbled across this idea. Thought, as for the IP Addresses on Minecraft Desktop-version, I have never seen IP's for other players, even for servers it has been something like "youcraftserver.verygames.net" or "pvp.pitforge.com".
What if our devices are already at the 0 subnet? "192.168.0.2" for her and "192.168.0.4" for me?