Last week, Stewart confessed that she had cheated on Pattinson with married Snow White and the Huntsman director Rupert Sanders, causing intense media speculation.
Stewart and Pattinson are due to begin a promotional tour for the final Twilight movie Breaking Dawn - Part 2 shortly, but Serratos suggested that ticket sales will not be affected by the affair.
"Of course people are fans of us now, but I think above anything, they're fans of these characters," she told Us Weekly.
"I don't think anyone's really gonna give a s**t. They're gonna see the movie; it's going to be awesome."
Serratos, who plays Angela in the Twilight Saga, also admitted that she wants the pair to work things out, saying: "I support anyone who's in love."
Reports today claimed that Pattinson is staying at Reese Witherspoon's California ranch in an attempt to recover from the news, while his representative was forced to deny rumours that he has cancelled a promotional appearance for his movie Cosmopolis.
Photo gallery - Robert Pattinson and Kristen Stewart's relationship in pictures: