
Her baptism entry — Sophia Joanna Elisabeth Retief, born 14 October 1839 at Swartland, parents Andries Joannes Retief and Anna Laker.
Swartland Baptism Registers 1836–1855, image 71 of 402 (DRC, Cape Town Archives). [link]
Daughter of Andries Johannes Retief (1817–1843) and Anne Laker. Her 1839 Swartland baptism register entry is one of the three primary documents anchoring the Gen 4–5–6 stretch of the spine: it independently confirms her parents’ marriage and places them at Swartland in 1839 — four years before her father’s early death. Named again on his 1843 Death Notice as one of his three minor heirs.

Her baptism entry — Sophia Joanna Elisabeth Retief, born 14 October 1839 at Swartland, parents Andries Joannes Retief and Anna Laker.
Swartland Baptism Registers 1836–1855, image 71 of 402 (DRC, Cape Town Archives). [link]
The 1843 Death Notice of Andries Johannes Retief — a single sheet at the Master's office that anchors Gen 4, 5 and 6 at once, and confirms the farm name Windhoek from the clerk's own hand.
Public trees quietly skipped Gen 5. The family kept them. The 1837 DRC marriage, the 1839 Swartland baptism, and the 1843 estate all say the family was right.
Andries Johannes Retief (Gen 5) died at twenty-five. His son and namesake was six when the estate was inventoried. The whole line continues only because the boy — and his sister — survived 1843.