She began writing serials for women's magazines, and published her first novel, Mavis of Green Hill, in 1920. In Baldwin's books, a reader will not find sex, poverty, depravity or evil. It doesn't matter what obstacles they face, the hero and the heroine always find happiness together at the end. Goodness and honor always triumph. It was a highly simplified version of life among the rich that especially appealed to the working girl and the housewife.
In 1936, Baldwin published three books that had earlier been serialized in magazines, along with five new magazine serials. The same year four of her novels were adapted for film. She made more than $315,000 that year.
For seven years, Baldwin also wrote a column called "The Open Door" for Women's Day magazine. She also served as host for Faith Baldwin Romance Theater, a weekly Saturday afternoon anthology series on ABC television.
When Random House publisher Bennett Cerf decided to start the Famous Writers School in the 1960s, he asked Baldwin to be one of the dozen "guiding faculty members," which also included Bruce Catton, Max Shulman, Red Smith, and Rod Serling. It was a heavily advertised correspondence school that returned its "faculty" stockholders handsome dividends at its height of $48 million a year in revenue. The school's fortunes subsided when it was revealed that a staff of 50 (none of them teachers) graded the assignments, not the famous writers themselves.
Baldwin continued to write until she died in 1978. Her last published novel was Adam's Eden (1977). She produced some 100 novels, among them Those Difficult Years (1925), The Office Wife (1930), Babs and Mary Lou (1931), District Nurse (1932), Manhattan Nights (1937), and He Married a Doctor (1944).