Aitken is also prolific in mixed doubles, where she has won the Scottish Mixed Doubles title five times. The first four championships, Aitken competed with her longtime teammate Bruce Mouat. Each Scottish title earned Aitken the right to represent Scotland at the World Mixed Doubles Championship, with her best finish being 4th at the 2016 Championship where they lost to the United States team of Joe Polo and Tabitha Peterson in the bronze medal match.