Simpson attended Diocesan School for Girls, Auckland, where she learned to play the organ.

[1] Simpson's grandfather Sir James Donald was also a politician in Auckland and she paid tribute to him in her maiden speech and wore the fob chain presented to him when he became deputy chairman of the Auckland Harbour Board in 1935.

At the 2016 Auckland elections, Simpson stood for the Ōrākei ward on the council, following an announcement by incumbent Cameron Brewer that he would not stand for re-election.

[5] Simpson stood for Communities and Residents, despite the formation of Auckland Future, a group supported by the National Party.

[8] The Mayor of Auckland, Phil Goff, appointed her as the deputy chair of the finance and performance committee.