i have 4 babies...there about 1 week into veg and i noticed that 2 have slightly bigger 2 bladed leafs then the other 2 and a bit taller. but its enough to be a difference and not just me hi or something so i there a corrolation?
I have noticed this on several grows, but it's not 100% reliable,
and may also depend on the strain.
Best to wait for the pre-flowers, but then again this may also depend on the strain.
Some strains give you clearly visable pre-flowers at around 4 weeks, while others are a complete mystery until you 12/12.