TightVNC is a free software that I have used to remotely connect to other people's machine as well as my local network in my house. You will need to install the software on his pc in "listen mode" as service (which means no icons on the system tray, totally invisible). An exception to the firewall has to be made for the program to be able to connect remotely from your son's pc if his pc firewall is on. You also have to know the name/ip address of his machine. Then install on your wife's pc.
You also have the option of viewing over Internet Explorer or the browser of your choice.
Hope this helps.
TightVNC: VNC-Compatible Free Remote Control Software
TightVNC: VNC-Compatible Free Remote Control Software