The couple went on to have a daughter, who they named after Sybil (Sybbie for short), but it all came undone when Sybil sadly and tragically died from complications during childbirth in 1920.

Which episode does Sybil die?

Episode 3.05 is the fifth episode of series three of Downton Abbey.

How did Sybil die?

Lady Sybil died of eclampsia, a condition of unknown cause that used to be called “toxemia of pregnancy.” (Dr. Clarkson, the family doc pushed aside in favor of silk-stocking-trade physician Sir Philip, used the term at one point.) It is most common in the late stage of first pregnancies.