She looks a little held back.
I am not experienced in coco growing, but, i do know you have to water every day, with nutrients, as coco holds very little of both.
And, imho, a little bit too cold. I´d go 20/night, 24-25/day
So for an auto in week 6, you need something. But need more info on the rest of your setup.
What kinda lights.? How many watts.?
In week 6 with coco growing auto´s, i am sure you should be pounding on PK atm, but there is no signs of flowering going on.
So my best guess would be, that it is actually NOT an auto, but a photoperiod, but still needs more than it gets atm. ( Nutes + light )