Born to Elijah McLean, a physician, and Mary Stafford, she enjoyed a privileged childhood with academic opportunities uncommon for girls of her time period.

Interested in continuing her missionary work abroad, McLean traveled to China and Japan, where she operated in hospitals and learned about Chinese medical education.

[1] Despite his age (fifty-seven years old at the time of his daughter's birth), Elijah McLean was determined to provide her with the finest education.

[2] With her father's influence and the help of a family friend, General Stevenson, McLean became an assistant physician at the St. Louis Female Hospital in 1884.

McLean was considered both a humanitarian and devout Presbyterian, who viewed her medical work as social reform and was as concerned with her patients' moral conditions as their physical ailments.

[citation needed] In 1885, with the support of her sponsor, the ophthalmologist Simon Pollak, McLean became the first woman to be admitted to the St. Louis Medical Society.

However, she encountered many obstacles in renting office space as landlords feared that the stigma of housing a female physician would lead to lower property values.

She finally found a residence on Olive Street in a neighborhood known as "Scab Row" but was not allowed to post any signs with her name or profession.

[1] One of her colleagues, Frances L. Bishop, described McLean's first few weeks in private practice: ″It was slow work establishing herself, for there were few women physicians.

"[2]In 1893, McLean and another female physician named Ella Marx opened the Evening Dispensary for Women at 1607 Washington Avenue.

"[4] The home remained open after the fair closed and affiliated with the Young Women's Christian Association (YWCA) in 1905, for which McLean served on the board of directors.

[3] She hoped to move there permanently but was forced to return to St. Louis after several months in Asia due to her poor health and the harsh climate.

[1] Once again, her colleague, Dr. Bishop, commented on her interest in learning more about this region and aiding the people who lived there:"She made several trips to China and hoped to locate (there) permanently, but climatic conditions did not warrant this.

For example, she secured a teaching job for Bertha van Hoosen, whom she had met at the University of Michigan, in order to help her raise funds for medical school.

One of her Chinese protégées, Dr. Li Yuin Tsao, became an intern for Van Hoosen once she had established a career in medicine in Chicago.