She was the co-founder of the Danske Kvindeforeningers Valgretsforbund or DKV (Danish Women's Society Suffrage Union) and first chairperson in 1889–1891.

Her spouse served as a vicar in a parish in Slesvig-Holsten, and the family was forced to leave for Varde when this part of Denmark was lost after the war in 1864.

In 1888, she delivered a list of 1702 names in support to Fredrik Bajer's motion in the parliament of women suffrage as the representative of the DK.

Luplau became one of the leading figures of the Danish women suffrage movement, and served on the board of the KF paper Hvad vi vil alongside Matilde Bajer, Anna Nielsen and Massi Bruhn.

In 1889, Luplau founded the Danish suffrage movement Kvindevalgretsforeningen (KVF) together with Louise Nørlund, and served as its chairperson from 1889 to 1891.