You might not have access to it depending on where you bought the game from. If you do have access to it, you'd find it here:
* Open Finder and navigate to the game folder for Virtual Families (it is placed on the desktop by default, but you may have moved it to Applications or another location)
* Open the Virtual Families folder
* Right-click (ctrl-click) on the Virtual Families application icon and click Show Package Contents
* Open the Contents folder, then the Resources folder, then open the Images folder