Jessica Keenan Wynn (born Jessica Armstrong, June 12, 1986) is an actress and singer known for her roles as Heather Chandler in Heathers: The Musical and Young Tanya in Mamma Mia! Here We Go Again. Personal life Wynn is the great-granddaughter of comedian Ed Wynn, the niece of Tracy Keenan Wynn and the granddaughter of Keenan Wynn, who is her namesake.