Veg time?

I have a small 4x2 so I don’t have much room. Have a gelato plant that is at 4 weeks from seed and I think it’s time to flower her. Can you all tell me what you think? I know you can veg anytime but with the space I’m wondering how much she’s going to stretch. I’ve topper her twice and lst her the best I could.

I would measure my space and grow my plant 1/3 of the height you have so when the stretch is done will not worry about it reaching in the lights. They say grow to half the hieght you want but subtract 12 inch or so for the light