Jace: He calls you 'honey' because you are so valuable to him. If you die so does he. He can't stand not to live with you in his arms.
Alec: Alec will call you 'shortia' or 'young'. Sortia because of you and his height difference. Then he calls you young because your the youngest of the group by a year.
Simon: Simon calls you 'cuddly bear' you always like to cuddle even during the most horrible time of day. You do like hugs a lot. Everyone did agree with the nickname.
Magnus: Magnus calls you glitter queen because you both love glitter and he is the king no matter what. Alec and izzy thinks it's weird but in a good way, I guess.
Raphael: Baby shadowhunter because you are his baby and your a shadowhunter. You hate when someone calls you baby but except when he does it.