All babies crawl at different times. Crawling at 6 months would be considered early. Some babies crawl as late as 10 months and later, some skip it all together. Some indicators that she is getting ready to crawl: she can roll over both ways, sit without support, go from sitting to a crawling position, and rock on all fours. But even this can last for a month or more. My baby rocked on all fours and scooted backwards for 6 weeks before she just took off across the floor one day. I would not encourage crawling; crawling early is not an indicator of intelligence, and it's a whole new ball game when they get mobile. It's really a pain...they no longer want to be confined, like in an exersaucer or johnny jumper. And you have to make sure everything is perfectly baby proofed...we had to mount our tv.
I started letting my baby try something other than babyfood around 6 months. I started with Puffs. At first she spit them out because she didn't know what to do with them. So I waited another week or two and tried again. Look for the pincer grap; if she can grasp a puff between her finger and thumb she is ready according to my pedi; I started mine a little earlier and she was fine. She got the pincer thing down sometime during month 7 about the time her first tooth came in. My daughter is 8 months today with 2 teeth and eats, puffs, avocados, potatoes, tomatoes, soft cheese in small amounts, zweiback toast (messy), regular toast, biter biscuits(supermessy!), mandarin oranges, yogurt, steamed carrots mashed up, peaches, lil crunchies from Gerber. She still eats her baby food mixed up thick with cereal but she likes the table food better. We are going to try some pastas in the next week or 2. I've also read, that when they can get up on all fours and hold their tummy up off the floor is a good time to start introducing more solids.
Everybody does this differently so you will just have to find what works for you and your baby.