First off, I do not own World of Warcraft and Princess Belorea is completely and totally fictional, she DOES NOT actually exist in the game, purely OC. Don't like her? That's okay, I completely respect your right to be against OC children of existing characters, no hard feelings whatsoever. Anyway, moving onto my idea. I am screwy on the timelines, I am open to my partner helping me tweak things to make them work better if it should be necessary.
Here is the basic idea, whether or not Belorea goes to Pandaria or someplace is completely negotiable for whatever ideas my partner might have to contribute. Without further delay, here we go:
Kael'Thas had daughter, his bride died in child birth. The young princess Belorea was left behind on Azeroth with the Kirin Tor's Varessa Windrunner and Rhonin when the prince left for Outlands, the pair loved and sheltered the girl as if she were their own, comforted her when Kael'Thas's betrayal was revealed to the then teenaged princess... they'd have told her sooner, but how do you explain such a thing to a small child? A deep scar was left on Belorea's broken heart from her father's actions, a terrible fear of magic and what could happen to her if she ever used any, she refused to ever become her father... as so many whispered behind her back that she would...
Kind and free spirited nonetheless, the princess chose to become a hunter when she reached adulthood for the Sin'Dorei race, learning her archery under none other than her adopted mother, Varessa.
She opted to abdicate her royal status completely and left her people in the capable hands of Lor'Themar, feeling it would not be right for her to take the throne given what her father had done.
Belorea has lived peacefully on Dalaran with her adopted family, practicing her skills in Crystalsong forest, waiting for the time when Varessa finally deemed her ready to journey towards her ultimate destiny as a heroic hunter.
Despite her desire to assist in the downfall of the Lich King, her adopted father Rhonin made her promise to stay out of it and to stay away from the danger until she was better prepared to handle it, explaining that her family could not bare to lose her. They loved her, regardless if she was not theirs by blood.
The death of her adopted father at the hands of Garrosh Hellscream however delayed her desire to strike off on her own, feeling instead that she was needed more at home with her adopted mother and younger siblings.
Belorea remained faithfully at Dalaran with her family up until the situation in Pandaria, the princess could feel in her heart of hearts that this was the cause she had been waiting for and she needed to forth and aid the Shado-Pan against the Sha, it took weeks to convince Varessa to allow her to jump into such a dangerous scene, but the princess soon found herself making the journey along with the accompaniment of a handful of Kirin Tor battle magi.