She growing very well, her main stem was 4mm thick on day 13 which means that plant left the seedling stage and she's thick enough to top it, to make 4 main nodes instead of 1 (topping autoflower is risky it may stunt your grow) you can aways try LST
Don't forget to use a small fan for air circulation
On day 12 distance from the light is 36cm (14") 640PPFD
No nutrients has been added, only water PH 5.8 - 6.0
Water your plant only if the top 5cm (2") of your soil feels dry if it's still wet leave it alone.