Name: "I'm Aaron, remember?" (Same last name as you)
Nickname: "Most people call me Aar. Pronounced air."
Age: "Same as you, or did you forget we're twins?"
Gender: "Definately not a girl." (Male)
Looks: "What? Do you need a reminder?"

Personality: "Jeez, what am I supposed to say?" (Sarcastic, protective, stragetical, logical, bit of a fraidy cat, dense.)
Other: "Uh... I like dancing?"

OR (Choose one)

Name: "Molly. You should know this." (Same last name)
Nickname: "You usually just call me Moll."
Age: "Same as you dummy."
Gender: "Most certainly female, thank you."
Looks: "You shouldn't need this but here."

Personality: "Um..." (adventurous, teasing, compassionate, sharp, silly, reckless)
Other: "I really like going on walks and gardening!"