it sounds like your doing all the right things, she may just be one of those bubs that walk a little later.
It's always hard to think of them doing it anytime soon but she may just up and surprise you, i always stressed DD1 would never crawl, she was 10mths before she did and i was so desperate for her to get moving.
She sat from 5mths and was such a PITA as she wouldn't reach for toys etc.... so set in her ways and stubborn!

GL, i don't think it's anything to worry about but maybe double check with the MCHN if your worried.