The actress, who plays Rosalie Hale in the franchise, attended the unveiling of The Twilight Saga: Breaking Dawn - Part 2 at the Nokia Theatre and promised to sign photographs at the event.
However, her generous gesture went awry when she headed back outside the venue to honour her vow and discovered most fans had already gone home - and she missed the movie screening as a result.
In a post on Twitter.com on Tuesday (13Nov12), Reed writes, ""Last night was so surreal. Twi-fans thank you for your endless support! I missed the film because I tried to go back out and sign for you as promised but most of you were already gone! Thank you guys for making this possible! We owe it all to you.""