First autoflower grow

The leaves look nice really good with a slight nute burn at the tip but other then that they look very healthy .

Zkittles autos were not my favorite grow. Extremely sensitive to N, K, P, wind burn light burn, and pH. Some were done in 9 weeks others 16 weeks. To be honest yours don't look bad at 52 days considering it probably took 3-4 weeks before flowers started to form. I would say have patience. They look healthy and may be on the longer life cycle.

Yep, they look fine, if you flipped to 12/12: 52 days ago. the first week of flower usually doesnt start for 1-2 weeks after flip. Which means most likely yhat youre in the 4th-5th week of flower. judging by the height, its likely a sativa dominant pheno, which flowers slower than indicas (generally) Dont worry too much about it, the plant will finish when it finishes, harvest based on your best judgement (bud /trichome development) and dont harvest based on age Best of luck with the rest of your grow!