- "It brings to mind the work of Jenny of Oldstones, the charlatan who claimed to descend from the Children of the Forest."
At the Citadel, the Archmaesters discuss a raven they have received from Bran Stark warning of the Night King and his army marching of Eastwatch-by-the-Sea. Since Bran claimed to have seen this through warging, one of them compared this to Jenny's claim that she was descended from the Children of the Forest.
In the books
In the A Song of Ice and Fire novels, Jenny of Oldstones was a poor woman who won the heart of Prince Duncan Targaryen and married him against the wishes of his father, King Aegon V Targaryen, due to the fact that he was already betrothed to the daughter of Lord Lyonel Baratheon. Aegon attempted to have the marriage undone, but Duncan refused to leave Jenny and gave up his right to the throne.
Lyonel was so enraged at the offense, however, of the Targaryens breaking the promised marriage betrothal, that the Stormlands rose up in a brief but bloody rebellion, culminating in an epic trial by combat between Lord Lyonel and his old friend Ser Duncan the Tall, now Aegon V's Lord Commander of the Kingsguard.
She was the inspiration for many songs, which famously remember her "with flowers in her hair". Jenny was a very popular romantic figure in later songs for many a young maiden (like Sansa Stark): Jenny, the commoner girl for whom the heir to the Iron Throne gave up his inheritance out of love.
When Prince Duncan met her, Jenny was a mysterious girl who lived half-wild in the ruins of Oldstones, which had once been the ruling castle for a dynasty of the First Men who were wiped out thousands of years before in the Andal Invasion. She claimed that she descended from those ancient kings of the First Men - though people from the surrounding villages mocked that she had no way of knowing that even if it was true. Jenny did not claim to be descended from the Children of the Forest, but a woods witch with whom she was friends with did make this claim about herself. This friend made a prophecy in which she claimed that the Prince That Was Promised would be born of the line of Prince Aerys II Targaryen and Rhaella Targaryen, which caused King Jaehaerys II Targaryen to arrange the marriage between his children.
Jenny was eventually accepted at court, even called "Lady Jenny" out of respect, and was beloved of the smallfolk throughout the realm. Prince Duncan later died in the great fire known as the Tragedy at Summerhall, but it is unrecorded exactly what happened to Jenny, or whether she survived or not.