Unless you mean is she a little bad, no. (Sorry, that is my lame humor.)
Little comes from some one way back when who was little, such as John Little in the tales of Robin Hood. Robin, much like myself, liked to turn names around and have fun with them, so he called John Little Little John. (John was a giant, standing more than 7' tall; tell your friend that.)
So, no, little is not a bad name, and any one who harrasses her is not only mean and spiteful but little emotionally.