Character design and drawing are tome-sized topics and even if I had all the answers (I don’t - I have a lot to learn), I’m not sure I could communicate them effectively. I’ve gathered some thoughts and ideas here, though, in case they’re helpful.
When a crystal gem has a child, that child inherits their gem stone and the parent gives up their physical form for their child. (We already know about this because of the “Laser light cannon” episode)
So each crystal gem gets a gem stone from one of their parents so that means every crystal gem has to lose either their mother or father to be born.