Erica Swanson is the sister of Paige Swanson.
Erica first appears in "A Rival Prodigy and Sir Isaac Neutron" when she and her family come over to the Cooper home for a play date. She spends her time with Georgie and Missy and throughout conversations between the three of them as well as their parents, it is revealed that Erica is ignored by her mother who pays attention to Paige most of the time, exactly like Georgie and Missy who are mostly neglected by their own mother.
In "Body Glitter and a Mall Safety Kit", Erica doesn't appear but is mentioned. Paige and Erica's parents, Barry and Linda, have gotten a divorce and Erica now lives with her father. It is revealed that she's crying all the time after the divorce.
- Like Georgie and Missy, Erica is often ignored by her mother who pays attention to Paige mostly.
- In her first appearance, she says she's in the eighth grade.
- She and Paige shared a room together before their parents' divorce.
- She become friends with Georgie and Missy. Unlike Missy, Sheldon is total pain.