Thinking about crawling

Bella has been working really hard on trying to crawl. She's figured out how to get up on all fours and today was moving her knees, but couldn't figure out how to get her arms to go along with them. Kayden was crawling at 7 1/2 months and walking at 9 1/2 and I've been chasing him since. I can only imagine how much busier my life is going to be when she gets mobile! All this, and she's only 22 weeks old!