The 21-year-old, who co-stars with the Oscar-winning actress in the Peter Jackson-directed drama The Lovely Bones, has insisted that she learned a great deal from acting alongside Sarandon.
Speaking to Teen Hollywood, McIver said: "Well, Susan is fantastic. I think she pushed me to see how far it could go. I think there were seven eggs on my head and a pound of oatmeal. She just went to town on me. I got some [cigarette] ash on me, a drink spilled on me. It was a very humbling experience.
"But, it was so flattering to be cast as somebody in her family. She's such a professional and has a lot of experience I feel like I learned a lot from working with her. But, eggs on my hair? I'm not really too fussy so it wasn't too bad. I felt like my skin was in better condition after that though."
As for working with 15-year-old Saoirse Ronan, she added: "We get along really well. I was very fortunate. We took to each other pretty quickly. She's so wise beyond her years. Really, she's more mature than me. We had a couple of weeks before shooting."
The Lovely Bones is currently playing in the US and arrives in UK cinemas on January 29.