It’s a bit early, if you decide to flush. I recommend waiting until you see a bit of amber, and note the number of days you start at. This is so you can change it on the next grow, if you want.
The more amber, the more couch lock you’ll have. I like to get about 75% amber, before harvest, and that would be a few more weeks.
I want to recommend another thread to you, as I personally don’t “final flush” ever, and think it’s a step that’s not required if you feed properly.
Very nice frost on her, by the way!
Good luck, and happy growing 