They are starting to flower.
Why would they be going back into veg?
Have you done freaky things with their light cycle?
I would not expect much stretch on 4 - 6 inch plants.
Hey. I assure you that if she has entered flowering, she won't go back to vegetative. The only thing she might do if she experiences a lot of stress is become hermaphrodite. She's probably in the stretch phase. I wish you all the best!