It appears that Margaret also signed Sheet 141 of the petition.
Biography contributed by Katherine Blakeley:
Mary Margaret/Maggie Thompson was born on 30 May 1868 in Glasgow, Scotland – the daughter of George Thompson, a shoemaker, and Agnes McMillan. (See 90 Mrs Thompson)
She emigrated to Otago with her family in 1874 on the Janet Court and they settled in Dunedin.
In 1887 Margaret married William Henry Trengrove, a butcher. They had four children together. Shortly after Margaret signed the suffrage petition, the family moved to the Christchurch area where William ran a butcher’s shop.
They moved back to Dunedin in later life where son John was running the Excelsior Hotel, which is where Margaret died on 10 February 1928. She is buried in the Northern Cemetery. William died in 1944 and he is buried in the Andersons Bay Cemetery.
Sources
BDM online NZ https://bdmhistoricalrecords.dia.govt.nz/
DCC Cemetery Records http://www.dunedin.govt.nz/facilities/cemeteries/cemeteries-search
Family Search https://www.familysearch.org
Otago Nominal Index http://marvin.otago.ac.nz
Papers Past https://paperspast.natlib.govt.nz