These days, they are both University of Otago students, Megan (23) in the fifth and final year of her Otago bachelor of dental surgery studies, and Olivia (18) studying first-year health sciences.
They came to New Zealand, initially to Wellington, with their parents and sister Grace in 1998, leaving Southam, a rural town in Warwickshire, in the English Midlands.
Becoming New Zealand citizens was a special moment, they said after the ceremony involving Dunedin Mayor Dave Cull at the Skeggs Gallery.
"It's quite important. I've always wanted to become a citizen," Olivia said.
It was good to gain citizenship recognition, given she had been living in New Zealand for a "long time".
They both enjoy life in Dunedin.
"It's great. I love it," Megan said.
The Octagon was "always buzzing" with activity and Dunedin people were "really friendly".
And her flatmates were preparing a pavlova, to celebrate last night.
The other new citizens were: Ali Jamil Al-Qahwaji (Jordan); Hani Muridi Amin (Somalia); Ruth Ansbacher, David French, Patrick Brown, Alexander Carruthers, Adrian Chamberlain, Struan Elliot, Paul Gell, Christopher Higgs, Shannon Kearns, Peter Lamsdale, Robyn Moore, Freya Moore, Martin Savory, Helen Savory, Steven Spelman (all Britain); Chathushka Basnayaka (Sri Lanka); Anna Davis (Sweden); Christopher Heng, Su Lee (Malaysia); Lana Davids, Tharon Knoetze, Irene Knoetze, Cornelius Niemand, Christopher Page, Alistair Raw, Brenda Raw, Timothy Raw, Tshegofatso Smous (South Africa); Rachna Luthra (India); Arawa Mohammed (Yemen); Eligio Sahagun, Edith Sahagun (Philippines); Edward Santagati, Sandy Thompson-Conklin (United States).