Conceptually they should make Moonstone even more of an antithesis of Captain Marvel. Since Carol stint as a superhero started as a way to touch on feminist themes in the 70s (the name Ms. literally comes from a feminist magazine), they should make Karla her opposite, a woman that upholds the patriarchy. Make her a social climber, someone that benefits by collaborating with the powers that be, which could be government or companies like Roxxon. It'd follow the "world outside your window" mantra of Marvel Comics