Can I LST at week 5?

Never too late for some low stress training. For such a big plant consider wiring up the stock with some coated wire. This way you can slowly bend the plant to the place you want. Otherwise only the top handful of nodes are trainable which can still yield some good results. A quick and aggressive solution would be to supercrop right as she enters flower.

I meant to say Yes you can LST. so NO it is NOT to late. Happy Growing

Yes, I LST and HST throughout the whole grow, The goal is to keep the canopy even. As she grows she will pick a dominate branch and start to shoot up on that branch. Then you LST that branch back to canopy level and she will start shooting up with a different branch.