There are only 2 people who may vote for Erika -- Marci & CG -- Marci, because he hates everyone, but since Erika did nothing, he has the least grudge against her. Also, Marci is immune to Dr. Delicious's hypnotic charm.
CG could go either way. I see him voting Boogie after listening to everyone in the house talk game play & strategy deserves to win, however CG is the type to place a sympathy vote.
None of the other HGs respect Erika or even think she deserves to be in the game, let alone the final 2, so none of them will vote for her.
Kind Creation of ARNutz