The name of the episode Emma will guest star is iFind Spencer Friends and will air next week, Oct 20th.
Plot: Carly and the gang try to find Spencer some adult friends, and along the way, they cross paths with a high-energy iCarly uberfan portrayed by Emma Stone.
About her character: Heather crosses paths with Carly and Spencer when the gang tries to find him some friends his own age, but she doesn't turn out to be as "adult" as Carly and the gang wished. She turns out to be a s "superfan" of iCarly. And has the same high enrgy as Spencer.