Diana having kids is such a non-starter anyway. It doesn't do anything for her character but provide microwave fodder. Babs makes a good comics mother because caretaking *changes* her - the stories you can tell with Cass and Charlie are significantly different from other Babs stories, and bring out a part of her personality that you don't otherwise see. What new part of Diana's personality does a kid bring out? I bet it'd make her maternal, and mama-bear protective, and she'd find herself in a teaching role with a lot of wisdom to impart, and hey wait.
That was an awkward build-up to me saying I've seen Diana/Darkseid fic.