hey lauralu.... i recall a recent post where you said you had about 20 lbs left to lose, so get ready for it, cause once that baby starts crawling, you're done for!!!
my first was sitting pretty much on her own from about 6.5 months. i would usually put the boppy behind her (around her?) and i think that really helped her. i know it's awful, but i
always had the tv on back when she was a baby, and she really got into it! but i think that helped her with sitting up because the tv was up off the floor and she had to sit up straighter to see it.....
my second.... shoot, i can't remember when she started sitting up. it was later than my first though.... maybe 9 months??? i was over that whole first time mom thing by then!
anyway, just sit and play with her.... hold fun toys up in front of her and keep them up out of her reach so she has to sit up and reach for them (that will help her strengthen her abdominal muscles). have fun and enjoy that baby!