Has flowering started?

Hi fellow growers :call_me_hand:

I am a newbie to growing and this is my first outdoor plant.
It seems to be going pretty okay for first timer, however I would like to know if she has started flowering or not so I can increase phosphorus levels.

She is also quite small, used a 15 liter pot. Will she grow more during flowering?

Appreciate any guidance :wink:

Looks like pre flower.

They can double in size during flower