Is it worth doing lst or topping despite its size?...

Hiya buddy. First I'd get that lady repotted. Then after a few days I'd top her. Maybe strip the bottoms a touch. She will get bigger if you give her a bit more pot. Make sure you add some Myco too. Try get her in a decent 7 gallon pot. Keep the light on 24 hours a day and she will soon start getting bigger. I do agree that more details would have been helpful but what I've said would apply to any plant. lST and top but first repot the girl. :)

Need more details about the grow lights, water schedule and nutrients all this is more important then training and topping.

Your plant looks stout and healthy for the most part, if you would like to have it branch out more I would recommend topping the last node. This will cause the plant to assume that is preventing it from expanding in that direction, therefore it the energy will be redirected to the lower nodes and it will begin to bush out. My main question however would be what light schedule is this particular plant following because it somewhat reminds me of an early flip to flowering. Additionally, your soil looks somewhat bone dry but it could simply be the top layer, but more access to water might encourage more vigorous growth. Hope this helps.

Topping it will make the other branches grow up for sure..those nodes are tight its gonna be short and dense

You don't have a diary for this grow? Without information, you're going to get garbage for answers here, sorry! For example, there's no way to tell what size pot that it or how tall the plant is - the pot could be a 4" pot or a 20 gallon... there's absolutely nothing we can even reference for size in the photo. Is this a photoperiod or autoflower? She looks almost like she's in flower but can't really tell... With no information, the MOST I would recommend is LST if you feel you have to do something. Good luck - and start a diary! That way, if problems/questions come up in the future, we'll have lots of information to inform our responses...