The actress, who plays vampire Rosalie Hale, quickly bonded with her co-stars while shooting the first Twilight movie in 2008 - but that quickly changed when they all shot to fame.
Now Reed admits she doesn't expect to meet up with her colleagues when they've finished promoting the final instalment, The Twilight Saga: Breaking Dawn - Part 2, next year (12).
She tells Seventeen magazine, "In the beginning, it was innocent and fun, and we were like one big happy family. It was like being at sleepaway camp. Success came along and changed the dynamic. We're not all best friends, and we're not all going to hang out together after the final movie is done."
"It was very, very sad. Let's just leave it at that. Attachments grow when you're working with the same people for so long. People are friends, people fall in love, people get in fights. We're not all robots in that way. Sure, things have gone on, and it's weird to have them be in the public eye."