Young Florence grew up in Cleveland, where her father shared his love of languages with her, teaching her Greek and Latin before she was a teenager.

[4] Allen graduated in 1904 with a Bachelor of Arts degree,[1] and her father then sent her to Berlin, German Empire, to continue her musical studies.

In order to pay her tuition, she found work as a legal investigator and researcher for the New York League for the Protection of Immigrants.

[2] As a child, her mother had taken her to see famous suffragists Susan B. Anthony and Anna Howard Shaw giving talks about women's rights.

And she argued one particular case that went all the way to the Ohio Supreme Court: thanks to her efforts, she won the women of East Cleveland the right to vote in municipal elections.

She also continued to advocate women's rights, even giving talks about her devotion to the Democratic party and the political process.

Undoubtedly, her biggest challenge was a case involving gangster Frank Motto, who was convicted of the murder of two men during a robbery.

[11] She continued to be a popular figure in Ohio, honored by numerous civic groups for her fair-mindedness;[12] and lawyers who came before her praised her willingness to listen.

[3] And while she was not afraid to make the difficult decisions, even on death penalty cases, Allen was not just a "law and order" judge.

She continued to give educational talks about the law, and she worked tirelessly to improve women's legal rights.

[3] By 1930, her reputation was so positive that some newspapers were suggesting that she be nominated for a seat on the United States Supreme Court.

[14] Allen was nominated by President Franklin D. Roosevelt on March 6, 1934, to a seat on the United States Court of Appeals for the Sixth Circuit vacated by Judge Smith Hickenlooper.

[1] Genevieve R. Cline was earlier appointed to serve as an Article I federal judge on the United States Customs Court.

In 1935, she was one of ten "outstanding American women", with Eleanor Roosevelt and feminist leader Carrie Chapman Catt, to contribute to Why Wars Must Cease.

In her essay, Allen asserted that wars "unleash demoralizing instincts" such as "callousness, cynicism, and greed."

[20] Allen was not named to the Supreme Court, however, and it was another male judge, William O. Douglas, who replaced Justice Brandeis.

"To secure peace, there must be justice," she told 3,000 attendees at a conference of the National Federation of Business and Professional Women's Clubs.

[24] In later talks, Allen expressed the opinion that while many women were in fact voting and speaking out on issues, there was a generational shift taking place.

Allen was later told that Truman's reluctance to appoint her had to do with his belief that having a woman around would make the male judges uncomfortable.

[1] In declining health after falling and breaking her hip, Allen died on September 12, 1966, in Waite Hill, Ohio, where she had been living with a distant cousin since her retirement.