The actress, who plays student Naomi Clark, joked to E! Online's Marc Malkin that she was "pushing" for 24-year-old Angel and Rachel, 20, to guest star in the CW show.
"I really would love to have my sisters on because they really are my best friends in the whole world. It would be really cool if they could come and be Naomi's two new friends," she said.
The 22-year-old went on to reiterate her desire to film a crossover with fellow CW programme Gossip Girl, joking: "I still want that to happen. I think if I keep speaking about it, it will happen."
McCord previously suggested that her character would be the perfect match for Gossip's Chuck Bass (Ed Westwick), saying: "I think the Beverly Hills bad girl should team up with New York's bad boy and have some fun. It would be naughty-naughty!"