Sara... it sounds to me like she's ready. If you want to start her, then go for it!! They say 6mths approx so that means give or take a few days/weeks... there is nothing exact about 6mths iykwim. As you know, we started DD at 5mths, 9 days we felt she was ready and she loved it! Opened her mouth and swallowed the mash banana and just seemed to know what to do! It was easy. I think you'll find that too.
And DD could sit up really well on her own (a bit supported), had lost the tongue thrust reflex or whatever you call it, could hold a spoon, was watching us eating all the time very curious, etc.... they are good signs they are ready.
It's more work but ALOT of fun!!!!
We are doing spoon feeding because I tried a bit of BLS and she just threw it over her shoulder and the spoon feeding is going great for us so we are sticking with it but soon might try a bit of BLS also.... (steamed carrot pieces etc)