Original sentence: They have two children: a son, Nick Tweed-Simmons, nicknamed "Lumpy" (born 22 January 1989), and a daughter, Sophie Tweed-Simmons (born 7 July 1992)
Edited sentence: They have two children: a son, Nick Tweed-Simmons (born 22 January 1989), and a daughter, Sophie Tweed-Simmons (born 7 July 1992)