Complex sentence: They had two children, a son Hugo (1929--1999) and a daughter Sarah or Sally (1934--1958), and lived at Ipsden House in Oxfordshire between 1930 and 1939.
Split into simpler sentences: They had two children, a son Hugo (1929--1999) and a daughter Sarah, also known as Sally (1934--1958). The family lived at Ipsden House in Oxfordshire between 1930 and 1939.