First indoor grow

Change your light cycle..she needs a nudge to flower.

Breeder says 12 weeks in total, so it's not too late. If they haven't started to show sex yet, they probably will very soon.

She's a sativa I believe so she should start flowering soon. You seem to be on schedule. Find something to wrap around your little res though, roots do not like light at all.

if you put her in middle, flayed her out, she'd easily fill space. they get nearly twice as large... so once you have 70%x70% (=~50%) it's likely good to go. if you flay it out like i suggested, i'd weave or prune where necessary. may need an extra cola here or there etc... use any tool at disposal to spread it out and even up height -- with consideration that anything cut might take an extra day.. maybe leave it a tad higher if given a choice. familiarity with rate of growth after various techniques will help keep it even. i'd have concerns about your height, so bend and/or cut her back down roughly to that net and go 12-12. however it works out best for even growth as mentioned above while also filling space of course.