Hmmm... Those girls look a lot like mine did when she was about 2 weeks pregnant. My girl is now four weeks pregnant (babies are due TODAY!!!) and it is obvious that she is expecting. You probably don't need a breeding cage quite yet; maybe in one or two weeks, you can put them in. For now, though, just keep an eye on them. Good luck!
One a different note... MY GUPPY IS DUE TODAY!!!!! OMGosh, I don't know what to do. Well, I do; I'm just soooo happy! Today, I saw her at the top of the tank with her anal and dorsal fins tucked in real tight against her body and she looked like she was pushing!!! No babies came out, though. After about 15 seconds, she decided that it wasn't going to work. These are some pics taken two days ago:
And one of the snail!
Let me know what you guys think!