hoping to get some advice on when to harvest.
Are the pix attached close up enuf to see the color change happening?
Checking the trichs with magnification is the best way to decide, however if your like myself and without the aid of a microscope or magnifying glass you can make your best guess on the trichs.
I generally start to flush when my girls seem to have fewer new white pistils than reddening/red ones, after a week they're probably 50%-60% red.
Looking at your pics, I would personally give 'em a few more days (maybe 5 days to a week), and start my flush, harvest after you've flushed for a week, you can go 14 days, but it's unnecessary.
Also, i wont be able to harvest my NL girl all in one chop - is it ok to cut branches and hang them all seperately?
Of course :
: Can harvest any way you want. Best way to dry is to hang them, some people use paper bags, this time round I've placed sheets of newspaper on shelves and put a layer of buds on the paper. Try not to allow buds to have direct contact with eachother and if drying by allowing them to lie exposed, you should rotate them every 24 hours to prevent mould.