Give it some more time and she will get big dude, i just know it.
If time is in question, shes got all the time she needs ;-)
Don't stres out Gonzo, she will grow bigger, I still don't feed mine plant she is 27 days old ( bio bizz all mix soil), she is as green as yours possibly a bit taller but we have different environment. So if she chose to grow bushy, let her ... She looks healthy, you doing well man
If I do not start feeding very soon and strong enough, they stretch and yields are poor. Especially under HS1 LED which tend to promote longer internodes. Hesi and Plagron Light Mix is not a good mix, I think. And soil is a pain all the time if you have too adjust ph manually, I mean with adding acids. That is why I am starting to test coco.