My 1st Sativa at D56 F - Please Help!!

Hi All,
Have an unidentified Sativa (UFO: Unidentified Flowering Object) at Day 56 of 12/12.
I don't know the Strain as was from a freebie pack from Amsterdam Seed Bank, and it's my first succesful Sativa.

Judging from these pics, how much longer roughly until she's ready to harvest?
All Trichs are showing clear under a 40x Scope and I'm in NO RUSH to chop as I have plenty of dried bud on hand.

She's currently sharing a closet with 2 White Widows which will probably be chopped at around Day 72 as things stand.

I just want an indication so I know when to end Nutes and start flushing my girl.

Thanks!

PS
Anyone know the Strain?
Care to take an educated guess?

skunk #1 maybe..

Thanks for the reply charlieb
I think it looks way too Sativa dominant to be that, plus the tell-tale odour isn't there.
The buds have an almost citrus odour when rubbed.
The leaves have 7 or 8 blades and are typical Sativa thin as can be seen in the pics.

Yeah skunk #1 is like the most common indica lol. Anyhow I recently ran pure haze and the flower time was ... exhausting. 115 days I think. It seemed less packed up with calyx's though unlike yours which to me seems like it's pretty close to completion. But most sativas are at least 65-80 days flower time from my experience depending on the strain. Outside of scopin out the trichs, something else to consider is the color of the pistils. Have the white pistils started to change to red yet or just some of them. Also I might try taking your trich sample from as close inside as you can get to the main cola and about 2" from the top and see what those trichs look like. If it were me I would chop if all the hairs go 50% red even if I still saw clear trichs vs cloudys and ambers. Hope that helps some. Enjoy her when she's done!

Thanks DurbanPoison
Only a few pistils have started changing colour at the moment [D60 Flowering].
I ended her nutes last night and will give only molasses in water 30ml/2l for the last 2 weeks and probably chop around D72 Flowering as planned.

Going by your username, you're obviously a Sativa fan - what do you recommend for a really energetic 'up' high?
I've got this girl on the grow atm, and have 2 x Nigerians currently vegeing as well as seeds for Nirvana's Jock Horror, Mandala Seeds Mandala #1 and Haze & Sativa Mexicana coming from the Sativa Seedbank via SeedBay.

Any crucial Sativas I'm missing?

BTW, your thread for your 250w stealth cabinet was an inspiration!
Now, where did I leave that 250w HPS...

Cheers!