At the age of sixteen, she married Prince Tristan. As soon as she became pregnant, Queen Enid forced her into confinement and constantly monitored her everyday activities, including her diet. She prohibited her from exercise of any kind, including going for a walk, and kept her room sparse, believing decorations would harm the child.
When Deirdre gave birth to the twins Aldous and Claudius, Enid supposedly suggested that she drown one of the infants to keep them from fighting over the throne. Horrified, Deirdre narrowly escaped the following night with her sons and went to her husband, who was equally appalled. While this may only be a legend, Tristan did begin to reduce his mother's power, culminating in her imprisonment in the Ivory Tower.
Deirdre bore a daughter, Helen, two years later, but never became pregnant again. The relationship between Deirdre and Tristan was observed to be on amicable terms, but they did not love each other.
Due to illness, she was not present at the tournament when Tristan was assassinated. After his death, Deirdre returned to Kronos and attempted to disassociate herself from her two sons, who were at that point embroiled in the War of Succession. She pleaded with Helen to come and live with her for her safety, but Helen refused.
She died not long after Claudius' execution, apparently of a heart attack. Some claim she committed suicide via poison, due to the grief of losing her son at the hands of his brother.