Is this flower?

Yes she is starting to flower. Probably around 7 days or so

Yes. It begins.

Yes...........she is about to start flowering in earnest.

Yes. It gets that extra leafy-mohawk look at terminal bud. You have preflowers at the nodes below, too. Single calyxes* form at each branch before anything else. The plant was in flower before you can see it. It takes time for new anatomy to grow. Human eyes can't resolve cells dividing. Figure 5-10 days before you see preflowers *Preflowers can form in vegetative phase of a photoperiod, if you keep it in vege phase long enough. But, this is very unlikely for autoflowers to occur given their time frame. You can safely assume it was in flower a week or so before you can see the preflowers of an auto. Depends on when we notice them.

Hi.... Das ist eindeutig die Vorblüte..... Durch die Zeitumstellung auf 12-12 ist sie in die Blüte gegangen....... Viel Glück

I checked your diary and would say its early flower :) The timeline is fitting with this being the second week after the switch to 12/12. During the next few days it will become more obvious and the first real buds will appear. Good luck with your grow!