My guess is:
Vault: Alicia, Shawn and Bridget
Bars: Nastia, Shawn and Chellsie
Beam: Shawn, Nastia and either Alicia or Bridget (most likely Alicia)
Floor: Shawn, Nastia and Alicia. I know Alicia had issues at the qualifying meet, but her record is solid on this event. Who knows...
I know she only competed on bars, just like Alicia, and on another thread here, I read that she sprained her ankle in warmup, but why isn't their any press coverage of that? It's pretty sad for both her and Chellsie that their olympic competition got watered down to competing on one event only...