After leaving Camille in San Francisco to go east with Sal, Dean meets Inez at a party in New York and quickly divorces Camille to marry her. Inez bears Dean a child, but then he leaves her behind to go find Sal in Denver and drive to Mexico to get a Mexican divorce from her.
The timeline below shows where the character Inez appears in On the Road. The colored dots and icons indicate which themes are associated with that appearance.
Part 3, Chapter 11
Part 4, Chapter 1
Part 5, Chapter 1