Nothern Lights - RQS

Honestly been lazy as f@#k in regards to posting lately. Besides co-vid I've got a family and 2 kids to take care of, studying and student placement, projects of all kinds. I'm sure all you growers have a life outside these walls ;) These 2 ladies are doing well, got a new 600watt HPS set-up, to allow a veg and flower space, and to be able to perpetually grow. 1 NL is about a week or 2 from harvest, but the other.... doesn't wanna flower. Just keeps on vegging. Checked her thoroughly and she is deffinately female, and no hermie. My philosophy, I'm pretty sure there was a tiny light leak hitting her during lights off time in the tent whilst in veg, enough to keep it in veg 24hrs a day whilst the others flowered. I discovered it late, changed both my light cycle to be lights off at night to avoid light leaks. It's a temp vs light leak battle sometimes. But my point now, how to make it flower without changing the light cycle and disturbing the other ladies? I'm looking to wait a week and see what happens before trying anything drastic. It has been about 4-5 days since transferring them from the tent to the flower space.