Stress induced flowering, is it possible?

Hi,
I am new to the forum. However I am pretty seasoned in growing. This year I was trying something new with surprising results.
I grow sativa dominant strain (Nebula) on a windowsill, plan being to veg for free and flower under the lamps. I grow four plants, two of the Nebula strain, both from seeds that came in the same package.
One plant I was stressing a lot. Second plant much more so.
I observed that the very much stressed plant was growing stocky with lots of branches. I would cut new branches split in two and top them and bend them and pinch them, every day a little bit, for five months or so. Not only did she show completely different growing pattern from her sister, which only has about 10 tops and it is stretchy, compared to 40 tops at height of 25 cms (70 cms in diameter).
I was keeping my favorite plant small since she is supposed to triple in height during flowering. But all of the sudden, on July 15th already, I noticed first flowers. The days are very very long, but she is happily flowering anyways. It is a bit of a problem, since I have room for one plant the exact size, precisely, and she may not fill it in now that her main stretch is nearly over.
Do you have experience with something similar? Can I induce flowering by stress? (I've never heard of it.) What can I do now? Should I revert her back to vegetative stage, artificially, risking hundreds of colas? Or should I flower my less stressed plant instead, or some other, and keep the monstrous one on my windowsill?

Pictures

5 months veg but still too small? perhaps the lightlevels are not fitting enough anymore, an old plant may begin to flower

First thing first. Paycheck in first, camera second, pictures third. I am sorry, three weeks to go. I had been too busy for a job the last couple of years. It looks sort of like during my previous years, only this time the plants are shorter and branchy. Setup is very similar.

Well, she is rather wide. I was deliberately trying her not to stretch. She is somewhat of this shape:

Imagine this being hollow. She is taking up three bottom rows at the moment. She needs to stretch all the way to orange area (1.5 m2, 40 cms from the light in all places, designed for 400 W HPS).

Trautenberg said:

Well, she is rather wide. I was deliberately trying her not to stretch. She is somewhat of this shape:
View attachment 4627673
Imagine this being hollow. She is taking up three bottom rows at the moment. She needs to stretch all the way to orange area (1.5 m2, 40 cms from the light in all places, designed for 400 W HPS).

Click to expand...

Just something that may be a good read for you if you’re delving into stress factors to do things to plants.

Thank you, nice read. I haven't found anything concerning my issue, however. I did find something on researchgate, but that was about ordinary, non-magic plants. I too believe in What doesn't kill you makes you stronger, and I agree with rest of the article as well, me being a former gardener.