I've just introduced a friend to soldat. I want to teach her how to play but if I make a server she can't join and if she makes a server I can't join, and we don't want any one else getting in the way.

It isn't a firewall problem, are there any other things that could be getting in the way?

read the stickies about setting up a server, or just go find an empty public server to play in with her.

yup, if you've tried that though and can't do it then give us some more details about how you're trying to go about playing.

are you on the same lan? or is this across the net? etc.....