I've done snow white and still keep it going. Started with 5 fem seeds. 2 died as seedlings but the 3 remaining grew real nice. Not a lot of stretch, maybe half it's size, so veg it to a nice height. Flowering is pretty long. 12 weeks to get it nice and ripe. You could cut after 10 but it's gets...
If your looking for a colorful sativa look into Killing Fields f2 from a breeder named Sannie. You can order directly from his web site.
http://www.sanniesshop.com/killing-fields-f2-p-684.html
Is that from seed or clone? If it's a clone do you know which cut it is? If from seed do you know which breeder? That may help with your answer. I think most chems go for around 9-11 weeks so you should be a week or two away. Looking nice , congrats on that!
Leave some lower branches with a little bud still on them, give it a good dose of veg fertilizer, and switch the lights back to 18 hours on. It may take weeks but the plant should start growing again.