The music icon is 72, while Streep is 69, but the age spread hardly bothers the “Believe” singer, who appears in the new Mamma Mia movie as the grandmother to Amanda Seyfried’s character.
“That doesn’t make any difference,” Cher said in PEOPLE’s exclusive Facebook live talk with the cast, moderated by PEOPLE deputy editor Dan Wakeford, about the small age gap. “I was thrilled to death, and it was so silly. It was great fun, and I love her [Meryl], so it was perfect.”
Cher continued, “It was great, and she was hiding watching me sing, and I was so excited. I didn’t find out until afterwards—I would have been more nervous.”
Though Cher and Streep mostly filmed on different days, they did get to spend time together on the set of the Mamma Mia sequel when Streep visited and when the duo filmed “Super Trouper.” Cher and Streep previously appeared together in the 1983 movie Silkwood.
And it turns out that Cher’s Mamma Mia roots run deep. “I was in an ABBA video that I actually forgot I was in,” she revealed.
Mamma Mia! Here We Go Again is out Friday.