I have similar thoughts. I'm not Sherri, and she knows more than I. But, on offense, I would station Nancy at the free throw line. She is an outstanding passer. We would have Vivi under the basket. If the defense comes out to Nancy, she can pass to Vivi. If they collapse inside as well, she someone on the wing will be wide open. It is tough for someone 6-0 to guard a player 6-9 without fouling. Nancy can hit a free throw jump shot at will.The UCLA mens team has a player named Thomas Welsh, who has a very similar skill set to that of Nancy, and he has a very similar build (7'0 and very long wingspan). He has a solid 15 foot jumper. On offense UCLA uses him as the four player and a much more physical, although a bit shorter, player at the five. although they don't do that for every single possession, there are times where welsh posts up and gets the easy lay in. On defense Welsh covers the opposing teams center for his shot blocking ability. Again, I am not saying this should be done every single possession with Nancy, but this could be done with Vivi who has shown she can score very efficiently around the basket and rebound very well.
On defense, just leave her near the basket. People will be afraid to shoot around her. They throw up strange shots rather than actually trying to hit the shot. She may block four. She will alter ten to twenty more. I've seen her catch shots with one hand and pass, almost in one motion.