That is a little bit early to start flowering but they look pretty good to me. The only thing is that the soil level is slightly low and that can cause air flow problems, especially if you have no actual extraction system. Cannabis loves its air. If you don't plan on potting up I would at least tip them out of those pots when it is next time for a watering (best when dry so that they come out easier and the weight of the soil doesn't break roots) and add a bit more soil to the bottom. That will give the roots more room too.

I am not familiar with your nutes but be sure you only water when they need it. Put your finger in the soil an inch or two and if it feels moist in there but dry on top then it's time to water. Or when they are smaller like that you can get a feel for the weight of the pot. Pick it up, when it feels light, probably time. Cannabis likes a bit of a wet/dry cycle so a day of being a bit on the dry side is typically OK.

Some white plastic sheeting might be nicer than the foil and less chance of spot cooking them.

They do take right off when put on 12/12. The growth for those first few weeks is amazing. Do you know what strain are you growing?

Good luck.