Hi again , i just want to answer first in general, and then back to your plant.
In general there is no iron rule when to change the Lighthours, for letting the Plant come into Floweringmode.
It depends in the strain , in your growspace, and how long your patience is too.
I mostly change to flower, if iam fine with my training.so i would say after 6 to 8 weeks.
Some strains i send in flower after only 2 weeks (( like asupersativa))...... because those tent to grow very unruly and large
If you are unsure, how long you should let her in vegetation, look for diaries of this Strain.
look into the Strain description, there the Breeders write down how much shes stretching
but mostly they double the Size.... sativals sometimes growing 5x in flower......
as it is your first grow and you did only alittle Training ( absolutely ok!!!)
you may let her grow a little more.
but if you are afraid your growspace is to small, send her to flower.