The "Mirror Mirror" star headed to the Mall of America in Bloomington with her "The Mortal Instruments: City Of Bones" co-stars Jamie Campbell Bower and Kevin Zegers to meet fans of the fantasy franchise.
However, one young girl fainted after receiving an autograph from Collins, who rushed to bring the 14-year-old a bottle of water, while Bower and Zegers helped her into a chair, reported New York Post.
"She made it past Lily but could barely breathe and then her legs collapsed. The guys helped her to her feet and sat her in a chair. Lily quickly got her a bottle of water," an onlooker said.