Someone is about to start crawling!!!

Yes, Greenlee is trying to crawl! What happened to my little baby?? This week she has been getting up on her knees and rocking back and forth. It looks like she could take off at any moment. She gets so excited when she is doing it too. I'm not too sure that I'm ready for two mobile kiddies, but ready or not here she comes! How do I get these things move?