The actress will appear again as Odin's wife and Thor and Loki's stepmother Frigga in the Marvel Studios film subtitled The Dark World.
"I think they're going to need a good mum in the next film," Russo told Vulture. "Loki needs his mum. What the hell?
"I have a lot of compassion for him. But we might have to have a conversation about what he just did. And I might have to have a chat with Thor."
The Thomas Crown Affair star revealed that she had been cut extensively from the previous film.
"[Director] Kenneth Branagh sent me a nice note, because he understood, he's an actor," she said. "You move on, what are you going to do?"
Russo also revealed that she would be reading up on her character for Thor 2.
"I am so confused - is Thor my son or not?" she said. "People have been telling me recently, 'No, you're not his mother'.
"It's all so confusing. I've got to tell you, it would be a little embarrassing if I don't know. I need to read more about her."
Thor: The Dark World has been scheduled for release on August 11, 2013.