Nobiko is a girl with fair skin and pinkish cheeks. She wears a purple dress with red overalls, and has brown hair and black eyes.
Nobiko has just been created with the Robot Family Maker. Hence, she has a tendency to be unclear when she speaks (e.g. When Nobita is making string figures, she actually said that he is "tasty" when she had meant he is "awesome"). She is very caring to her brother, especially when she is cheering him up during baseball practice.
However, she is inclined to throw tantrums and get angry sometimes. When Nobiko brings a cat to "help" in tidying Shizuka's room, it messes her room instead and she gets mad at Shizuka for making her cry. She also has a tendency to misunderstand words; when Nobita feels that having a younger sister is tiring, Nobiko mistook Nobita for wanting more younger sisters and makes many clones of herself.