“Marie is seemingly quieter and not as excitable as her cousin, and usually only gives a half-smile, if at all. She can be sarcastic from time to time, and slightly prone to complaining, but is usually in a mild mood. Overall, her disposition is laid-back and friendly, but sometimes grumpy. She is also an expert at doing impressions, as mentioned by Agent 1.
She dislikes overly-thrilling activities, and can even be somewhat lazy. She also does not seem to be a big fan of tomatoes.” -The Splatoon Wiki