She's crawling!

When do usually babies start to crawl or sit? Better yet, which one comes first? I'm rather confused but excited at the same time because we just witnessed Baby K crawl. Still don't believe me? Here's the proof:

She is still slow, gets tired and gets off balanced from time to time but she is crawling. She will crawl especially when she sees a lit up cellphone nearby. She is so cute and starting to be really on the move. She knows how to wave too. When you say hi, she'll mumble and starts waving at you. I'm so happy and anxious at the same time. This means that I'll be chasing after her from time to time. I've been putting pillows every where so if ever she gets tired or gets off balanced, she won't bump into a hard table and vases. I guess she'll be sitting next month? I'm not sure but it makes me so excited. She's turning 7 months next week too. This is just too fast for me, I need to have a pause button.