Michael Eavis’s daughter who co-organizes the Glastonbury Festival is Emily Eavis.
Emily Rose Eavis was born on 26 July 1979 and grew up at Worthy Farm, the family dairy farm where the festival takes place. She is the youngest daughter of Michael Eavis and Jean Eavis. Her early life was closely connected with the event: at the age of five, she performed “Twinkle, Twinkle, Little Star” on the Pyramid Stage in 1985.
After her mother became ill and died in 1999, Emily began assisting her father with the festival and became its co-organiser. She gradually took on a major role in booking artists and shaping the event’s programme, including the creation of The Park area in 2007 and the booking of Jay-Z as the first hip-hop headliner in 2008.
The answer is Emily, not Emma. Although the names sound similar, Emily Eavis is the specific organiser associated with the festival. Her husband, Nick Dewey, has also worked closely with her on music programming and festival organisation.