Not to be confused with Eva.
In "The Revenge", Ava is present at the meeting where Levitan berates and fires George in front of the whole office. She is also present at the office party where George poisons Levitan by "slipping a mickey" in his drink.
In "The Stranded", Ava attends the party in Long Island at Steve's house, where she and George start up a romantic relationship, in which she tells him to "make love to [her]." Before leaving the party Ava and Elaine get into an argument over Ava's fur coat. George and Ava start a relationship, which ultimately turns out to be George's worst nightmare: since they work together, every day feels like a date.