Gyanna is the spitting image of her grandmother, Sylva Fowler, who became well known throughout Dorne and beyond as the woman who helped secure their freedom. Following the conquest, Sylva became Lady Yronwood and lived to the old age of seventy, sharp and smiling to the end. She absolutely adored her lookalike granddaughter and spoiled her above the others, and left Gyanna all her jewels and prized possessions, including a fragment of scale from the great Morkhuul and sultry notes she had exchanged with King Naeros. She claimed many times that Gyanna was meant to be more than a mere princess and that the gods had plans for her, much to the girl's delight.

Little was denied to Gyanna growing up. She was allowed to run almost as free as her grandmother. Though she had no mountains to conquer, the girl did learn the coastal areas of Dorne like the back of her hand, and even in a vicious sandstorm with little visibility, she always knew where to go to seek shelter. She mastered swimming and horse-riding and learned to use a Braavosi blade quite capably, and also took up more womanly pursuits, like the harp, singing and, of course, dancing.

She and her siblings travelled the East for a year in their teens, visiting the free cities and learning of their customs—and making important contacts, of course. Even then at age fifteen, she received too many marriage proposals for her parents to keep track of. Her father only betrothed her a year ago, however, though ultimately the marriage did not come to be, due to her betrothed treading on a poisonous snake the night before the ceremony. He had been drunk, witnesses said, and was running about without his boots on. Some others have whispered that the Prince had been looking to get out of the betrothal, for he was in secret talks with the Iron Throne to give her hand to Visaron.

Although Gyanna and her siblings are each quite unique in outlook and personality, they get along fairly well, despite the habitual squabbles. There is no real jealousy or backstabbing, perhaps due to the fact that they each have their own little niche and do not feel threatened by the others.