too soon to tell by these pictures, but you should be looking at the top of the plant, not the bottom, signs of sex should appear at the top 3 nodes first.
Take a clone from each one and put it under 12/12 light for 1 1/2 weeks and the clones will show. Unless you are ready to put the entire plant under 12/12. Then just do it and wait the 1 1/2 to 2 weeks they will show 2 white pistols if they are female.
i think it's a girl but it's hard to say for sure from the pics. in my experiences, males are easiest to tell apart as they start growing balls before they even get to 12/12. do you see 2 pointy horns near the nodes? then female. do you see clawed-hand-like parts growing and opening up? then male.
i've also found that you can put your plant in 12/12 for long enough till it shows hairs. you can then put it back into 24 hour light to stop the flowering process.