Donna should never be her twin. She should be her younger adopted sister.
Jason just shouldn't. He can be her twin on Earth 52, but not in main continuity
If there has to be a twin, then it should be Nubia. I also don't mind her as just being Diana's sister, but I can see where being Diana's twin automatically informs the character with a certain weight and sense of equality to Diana. And they should be sculpted of clay, none of this daddy Zeus garbage ��