Other than height, I don't see much of a comparison of Nancy to either Griner or DeHaan. All three are very different types of players. DeHaan was just tall with almost no skills. Griner came in as very unskilled, but developed the ability to shoot free throws and a short jumper to become a solid offensive force. She was a good shot-blocker. But, she never came around as a rebounder, leaving that up to her forwards.
Nancy has a much better overall game than any of these at this stage. She is trained to play basketball: pass, shoot, dribble, and block shots. She is not a great rebounder, but we don't really know how good she is in that respect. That wasn't what her team wanted her for. She was the best that I have ever seen in highschool at changing the nature of the opposition offense. She just gums up their works. She blocks shots, but those hands are everywhere, and they begin taking stupid shots. She is as good of a shooter now as Griner ever became. She probably doesn't have what became a solid forte of Griner, mobility. But, she is a lot smarter than Griner on how to use her size. Having an aunt and mother with a history in the game has been useful.
If we put Nancy out there and expect Courtney, we'll be disappointed. But, what Nancy does provide is the ability for a forward or driving guard to operate without much of a defensive concentration. She could play a point-center position. If we have a power forward step up, she could become an All-American name with Nancy clearing a path.
We need to remember to keep Nancy out of foul trouble---no bringing the hands down to block shots. Keep them high and alter shots, or catch them. Don't take charges. They'll be afraid to shoot anyhow.