Here you can add Ring Card Girls. Click on Edit, then choose new. I've added Brittney Palmer here as an example.

For Windows go to Computer/Libraries/My Documents/tbcb2013/data/images/ring card girls.

The best image sizes is 140x140 in jpeg format. Images should be Lastname firstname as in Palmer Brittney. Inside the game click on the Ring Card Girl Button, click Edit in the upper right corner and click New. Then just input the Ring Card Girls first and last name, save then go back to the Ring Card Girl list screen. The next time you access the individual Ring Card Girl record her picture will be there.

Note: If you already have Ring Card Girls added from 2.5 simply import your universe and they will be there. If you start a new universe, the Ring Card Girls will be there already, you simply have to add their names to the list from the game.