Darline Graham Nordone, the sister of the late U.S. Senator Lindsey Graham, has been appointed to serve as his temporary replacement in the Senate, South Carolina Governor Henry McMaster announced Monday.

Nordone will serve out the remainder of Graham's current term, which is set to conclude in 2027. Graham, a Republican, died on Saturday at the age of 71 due to an aortic dissection, a condition related to cardiovascular disease, according to preliminary findings from the medical examiner.

"It is such an honour. Lindsey has always been there for me and now I will be there for him," Nordone said following the announcement. "I believe this is what Lindsey would have wanted and I plan to honour him in this way."

Governor McMaster stated that Graham had been a devoted caretaker to his sister, and that appointing her to finish his work was an honor. President Donald Trump was among those who had called for Nordone to be appointed as Graham's successor in a tribute to the senator.

Lindsey Graham, who never married and had no children, was legally adopted by his parents. His sister, Darline, was 13 when their mother and father died within 15 months of each other. Graham, then 22, maintained a close relationship with her as he pursued his education and military service. In 2015, Nordone described her brother as being like "a brother, a father and a mother rolled into one." Graham later adopted her, stating it was to ensure she would receive his military benefits.

Nordone, who has two children and works in disability services, has been a consistent presence throughout her brother's political career. Graham had previously suggested she could serve as his first lady if he were elected president.

Graham had secured the Republican Party's nomination for re-election in November. Several other Republican candidates have already announced their intentions to run for his Senate seat.