So I've been growing 3 plants that I thought ...

Seeds are from ilgm beginner mix autos the White Widow is 7 and half weeks old and the other 2 are 7 weeks

I would say to wait a week or two if you have the height. Some strains can take longer then others to flip. I can see one plant reverting back to photo but 3 plants would be rare from a reputable company. Take a look at this grow. It was week 7-8 that they started to flower. growdiaries.com/diaries/103495-grow-journal-by-roberts/week/565250 Once you start to run out of space( plant is half the height of your max light height(minus light to plant distance) Then consider flipping.

Two look much different.. I dunno man some autos can go 6ish weeks but much further it’s likely a photo. I’d just switch to 12/12 at this point.. you could wait another week or so just to be sure..