Is is Kati Farkas' best friend and they often attend parties or try to get invitations to exclusive events. They are inseparable.
Isabel appears in the Pilot, noting that someone saw Serena van der Woodsen get off a train at Grand Central Terminal. She appears throughout the rest of the season alongside the other girls, Kati Farkas, Penelope Shafai, Hazel Williams, Nelly Yuki, and Jenny Humphrey. In The Blair Bitch Project she reveals she broke her arm during spring break in a spa at a ski resort.
Throughout the second season, Isabel appears with the other girls; namely Penelope, Hazel, and Nelly. In It's a Wonderful Lie, she buys a dress to wear to the Snowflake Ball that ends up being see through. She then gives it to Jenny to humiliate Vanessa Abrams with. In the season finale The Goodbye Gossip Girl, Isabel graduates alongside everyone else and helps the other girls almost crown Emma Boardman the new queen.
- She is a concert pianist.
- She never wears the same outfit twice.
- She once broke her arm in the spa at a ski resort.
- Warren Buffet is her godfather.