I'm using Windows Vista, and mine is located at:

C:\Program Files\Virtual Families\Images

You might've saved it somewhere else, so if you want to figure out where it went, look for the shortcut to the game on your desktop or in the "All Programs" section, right click it and select "Properties".

That'll show you where your virtual families folder is saved under "Start in" and you can locate it there. Even easier, you can select "Open file location" instead of Properties and it'll take you right to it. Good luck!