Inhabitants of the island gained U.S. citizenship in 1917, two decades after the United States acquired Puerto Rico from Spain in the Spanish–American War.

Benet was active in the struggle for women's enfranchisement and joined the first suffragist organization Liga Femínea Puertorriqueña that year.

When U.S. women gained the right to vote with the passage of the 19th Amendment in 1919, Benet led the push to extend its coverage to Puerto Rico.

The Supreme Court of Puerto Rico ruled that states and territories have the right to determine who can vote and denied her claim.

[28] That year, the Puerto Rican Feminist League (Spanish: Liga Femínea Puertorriqueña) was founded by Ana Roqué.

[40][41] Both she and Mariana Morales Bernard, a leader in the women's labor movement, filed court cases to assess the applicability of the 19th Amendment to Puerto Rico,[42] as had been suggested by José Tous Soto, after the 1923 bill had been rejected in the Senate.

[29][42] Fearing that an alliance with working-class women would promote the spread of socialism, under the leadership of president Rosario Bellber the conservative faction of La Liga resigned from the organization.

The liberal faction, many of whom were members of the Pure Republican Party (Spanish: Partido Republicano Puro), were led by Benet.

[42] New elections for La Liga were held among the remaining members who supported developing universal suffrage and maintaining the links of republicans and socialists.

[51] Though La Liga continued to press for universal suffrage, they acknowledged that they would support giving the franchise to literate women alone, as a stepping stone for full voting rights.

[57] She is remembered today for her activism in the fight for women's suffrage in Puerto Rico[58] and an analysis of her life points to the impact she had upon gaining the right to vote.

They had little impact on the legal discussion of citizenship and as their organizational efforts focused on unionization and socialism, they were ineffective in organizing for broader appeal.

[40][59] When Benet, a member of the elite, filed her suit against the electoral board, she had the support of the liberal intellectual community, as well as a network of influential men who saw voting as an extension of democracy.