Why not use V3 or V4 male?  You can use the original for the girl and then inject the male morphs to create the boy.  Because the faces are the same, you can make minor changes so that they still look like they are related.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi