How to set up VNC?

[Scott & Danielle Gittoes]

Hello
 
My mum has just got a new computer and I am trying to teach her how to use
it, so thought I would get VNC running so I can see her desktop and show her
exactly what to do.
 
We have both installed  the free edition of VNC.
 
But I can't connect to her computer as a client
 
Her IP is showing as 192.168.1.2 - which I think is a private IP address?
 
Is this coming from her ADSL modem?  How do I find her actual IP address so
I can connect to her PC?
 
Thanks
Danielle