Granddaughter of Lyman Beesbury, the Master of Coin, and a soft-hearted soul, Sybilla was a reserved young woman, oft lost in her own thoughts. Many dismissed her as empty-headed and lacklustre. After the death of her grandsire at the hands of Ser Criston Cole, she was taken into the service of Queen Alicent Hightower as one of her ladies-in-waiting, rather than left to languish in the Black Cells. To preserve her own life, Sybilla publicly renounced her grandsire's cause, refusing to speak of him or align herself with the rest of House Beesbury at Honeyholt.
It was during her service that she came to know the Queen's brother, Ser Gwayne Hightower, whose company shook her patient composure for which she had long been known. Bitter letters from her father only deepened the rift between Sybilla and her kin, and before long she agreed to wed Ser Gwayne. Their daughter, Alyrie, named for Gwayne's lady mother, Alyrie of House Florent, was born.
Gwayne Hightower's death during the Riot of King's Landing, followed by Sybilla's capture at the hands of Queen Rhaenyra's forces, left her fearful for both herself and her infant daughter, whom she refused to let from her sight. Only after Daemon and Aemond Targaryen slew one another above the Gods Eye, and Queen Rhaenyra was driven from King's Landing, did Sybilla allow herself to breathe more easily. Before the Hour of the Wolf, she escaped the city with the aid of a handful of old connections, smuggling Alyrie across the narrow sea to Lys. There the two found refuge in a pleasure house, living quietly beneath assumed names whilst the realm believed them long dead.
