Let me try and piece together the sequence of events...
Sherine launches a world-coup against Bayeswatch hegemony
Vi and Miriam take out Sherine’s headquarters
Bayeswatch nominally reestablishes control, but their vulnerability is known
The hivemind starts building a military force
Vi joins/seizes the hivemind
The singularity war starts. Vi controls the Bayeswatch-loyal side.
Sherine-controlled Miriam kills Vi’s original body
Vi’s forces lose the war for control of Earth’s surface but launch a von Neumann probe
Before drafting this I was wondering if Vi started the singularity war. But if she controlled the singularity and the Bayeswatch-loyal human forces, she probably would have won.
Unclear if Sherine a) is behind the singularity, b) sides with the singularity over Vi, c) thinks a third faction can defeat both Vi and the singularity, or d) figures humanity is doomed no matter what so she might as well get some revenge. Her em’s dying words suggest a).