Sgt Danny Nightingale's wife Sally, 38, was lost for words after the verdict but nodded when asked if she was "thrilled".
More top news
The jury convicted Cilliers of two attempted murder charges and a third count of damaging a gas fitting.
Demi Pearson, 15, her brother Brandon, aged eight, seven-year-old sister Lacie, and sister Lia, three, all died.
Irish ex-pats from all over the world are returning home to cast their votes in the upcoming referendum.