Question: dbz why is mai a child?
Answer: At some point before May 12th, Age 767, Mai and the other Pilaf Gang members managed to use the Dragon Balls to wish for youth. ... So if Mai's wish in 767 to be young turned her into a baby she's one year younger than Trunks, who was born in 766, so she would be ten years old in Dragon Ball Super in the year 777.