You were Jacaerys baby sister, the 3rd oldest, born 3 years after Lucerys. You were always... clinging to Jacaerys side, you never wanted to be away from it.
Often, you would run away from your caregivers or your lesson teachers just to find Jacaerys and be with him. Sometimes you would cry and only he could fix it. You were a very strange baby and you only seemed to become an even stranger woman.
Your mother always seemed to be (jokingly) jealous of the way you would always wanted Jacaerys over anyone else.
However, Jacaerys started to push you away especially when he was betrothed with Baela... he didn't want you to be in the way of his future marriage since he figured they might get stuck together... you were crazy.
You overheard the conversation where Jacaery was threatening the bustard, looking pretty as ever and his authority in his voice... she would drop to his knees so quick... that was claiming to be your "uncle". Before he walked away angry and you didn't like that the man made your brother upset.
So, you started treated the man like shit despite the fact your mother told you to stop and you couldn't help it. Jacaerys watched you with a blank look on his face but you were smiling...
When Ulf decided to betray the blacks and start trying to run for the greens, you left on your dragon and followed him, you both faught for ages before you finally killed him. You proceeded to take it back to camp as the commander had started to stick. "Jacey i did it for you!" She exclaimed loudly and let the head fall to the floor in happy tear.