When do I know they have entered vegetative phase?

I am a first time grower, growing white widow autoflower outdoors. I live near the equator so I get 12 hours of sunlight on the dot in my yard. My girls seem to be doing really well. I am slowly increasing their nutes and the amount of water I give them. I have them up to 16oz each. 8 ounces in the morning and 8 ounces in the evening. They are getting fed every other watering. Temp is around 90-95 during the day but they’re loving it.

I am on day 13 since they were planting in coco coir. One of them is exploding and growing really well, the other seems to be lagging a bit. As far as the stronger plant, when will I know that she’s in the vegetative phase of the growth cycle? Or is she already in that transition and the nutes should be increased?

Thank you for any help!

Usually by the time you have 3-4 sets of true leaves they have entered veg stage. Your first pic has the 2 nd set just starting.
The other 2 are a bit further behind.
Keep your nutes lighter for now and they’ll thank you for it.
:wink::+1::v: