What cahill branch do Amy and dan find out they are in the 7th book?

In the seventh book of the *A Series of Unfortunate Events* series, *The Vile Village*, Amy and Dan are revealed to be members of the Baudelaire branch of the VFD.

This is a significant revelation, as it means they are related to Violet, Klaus, and Sunny, although they haven't yet met. The Baudelaire orphans are also members of the VFD, and their lineage is connected to Count Olaf, who is also a member but is on the wrong side.