It's difficult to tell the difference between sexes when water dragons are juveniles.. The easy way is to wait until there around 18months old, males will have a much larger head and broader shoulders and the crest on the back of the neck is a lot bigger.. Another way to tell is the difference in colouring, males will have a large dark red area on there stomachs though female can also have a faint orange,red colour on there chest.. Generally males will have much more colour to impress the ladies but the female will be very dull in colouring..
Males in both Eastern & Gippsland are chunky, bigger heads, stocky bodies & tails. Females are more slender.
Females can have just as much colour as the males so you cant solely rely on colouration, although combined with body structure it can give you a definate answer.
even in quite young water dragons,the deep red of males starts to appear,so can usually tell a male,though some dont always develop it so deep so harder to pick females,once they start getting some size,males will tank out ,especially the head,also the females get a different eye band to males