They are a bit too young. You can tell when they get a big black dot in the middle of their body. If there are blue speckles inside of the black dot, its a male. If no blue speckles are inside the black dot, it is a female.
Its hard to see normally and I can’t see it all in your pics. It has to do with the vents near the analfin. The male’s is smaller and points straight back, while the female’s is squared off and points downward.