[3][4] Born in China and raised in New York City, Lee received a bachelor's degree and master's degree from Barnard College of Columbia University, and later a doctorate in economics from Columbia University in 1921, becoming the first Chinese woman in the United States to earn a doctorate in economics.

In recognition of her life and advocacy on behalf of women and Chinese immigrants in the United States, the Chinatown U.S. Post Office on Doyers Street was renamed in her honor in 2017.

She wrote articles for The Chinese Students’ Monthly, in which she championed for woman's suffrage and argued for equality as necessary in a democracy.

The Chinese government was impressed with her research in the agricultural economy and granted her a Boxer Indemnity Scholarship which allowed her to continue her studies.

A local Baptist newspaper reported, "On March 28, 1923, Miss Lee sailed for France where she is now engaged in the study of European Economics, in fuller preparation for her life work, in her native land, China.

"[12] Lee had numerous job opportunities including an offer from a Chinese firm interested in trade from the United States to China.

Racial and sexist discrimination were likely to reduce her chances of attaining her goals and it became unsafe to live in China with the Japanese invasion and the start of the Second Sino-Japanese War.

[13][15] Before she was writing essays advocating equality in The Chinese Students’ Monthly, she was riding horseback as a teenager in the campaign for women's suffrage in New York state.

Shaw carried a National American Woman Suffrage Association banner that stated: "N.A.W.S.A Catching Up with China" while Lee rode on horseback.

[3] In a 1914 issue of The Chinese Students' Monthly, Lee wrote that feminism is “the extension of democracy or social justice and equality of opportunities to women”.

While Lee fought for equality and the right to vote, she and other immigrant women, were unable to reap the benefits until years later.

"[22]When Mabel Lee's father died from a heart attack in 1924, she took over his role as head of the Baptist mission in Chinatown at the age of 28.

Lee traveled three times to China during the 1920s and 1930s, and even had job offers awaiting her there, but she eventually chose to settle permanently in New York and focus on her father's church.

Lee believed that an independent Chinese church was crucial for providing support and a feeling of freedom to its community members, who were otherwise marginalized and oppressed in American society.

[15] Lee's view that there needed to be a Chinese Christianity and not a European American Protestantism sometimes brought her into conflict with the larger white-led Baptist mission in New York City.

In 1954, Lee was able to secure the title of the 21 Pell Street property solely under First Chinese Baptist Church which from then on became fully independent.

Paradoxically, this independence coincided with the increasing secularization of younger generations of Chinese Americans, and led to dwindling membership at the church.

[12][24] The First Chinese Baptist Church is still standing and continues to offer the social services Lee started and strives to maintain the community's civil rights she fought for.

[16][14] In November 2017, a motion was introduced in Congress by Rep. Nydia Velazquez to rename the Chinatown Station U.S. Post Office at 6 Doyers Street in honor of Mabel Lee.

[29] Mabel Ping-Hua Lee was featured in the New York Times Overlooked series obituaries on remarkable people whose deaths initially went unreported in newspaper in September 2020.