New growers often ask 'how can I tell if it's a girl'?
It's not difficult really once you know what to look for and when.
For normal photoperiod plants they usually show from the 4th/5th week of life and are usually located on the 3-5th branching node. This happens from the 3rd week of life when growing autos. If you look carefully at the branching points you will see that little calyx with a creamy white double pistil coming out which confirms you've got a girl that's sexually maturing and about ready to flower.
The easiest way to demonstrate this is simply with a couple of pics that show what the first little calyx/pistil looks like :
35Days-FemalePreflowers-Regular-HarlottoStrain.png 1.3MB 0 downloads
Pre-flower-01.jpg 103.52KB 0 downloads
Shimples