They are both alumnae of Central High School in Sioux City and Morningside College, where they both studied journalism and psychology, along with writing a joint gossip column for the college newspaper. They both played the violin. In July 1939, they were married in a double-wedding ceremony on July 2, two days before their 21st birthday. Pauline married Morton Phillips of Minneapolis, and had two children, a son, Edward Jay Phillips, and a daughter, Jeanne Phillips.

Like her sister, Phillips was considered "the embodiment of female orthodoxy." They made their husbands and families a high priority in their lives, feeling that "marriage must be permanent, even when disturbed by masculine lunacy." Phillips typically spoke in glowing terms about her husband in public, calling him "loveboat" or smooching with him in restaurants. This attitude carried over into their columns in the late 1950s, with Phillips considering women who were unable to make their marriages work as "faintly ridiculous." Her "code of conduct" was "husband and children first." In her later years, she did not avoid suggesting divorce when a relationship became "intolerable", and considered how a bad marriage might affect children: "When kids see parents fighting, or even sniping at each other, I think it is terribly damaging."

Pauline Esther Friedman, nicknamed "Popo", was born in Sioux City, Iowa to Russian Jewish immigrants, Rebecca (née Rushall) and Abraham B. Friedman, owner of a chain of movie theaters. She was the youngest of four sisters and grew up in Sioux City. Her identical twin, Esther Pauline Friedman (married name Lederer), was columnist Ann Landers. Lederer had become Ann Landers in 1955, and inspired by her sister's Example, Phillips soon followed suit by launching her own advice column.

Phillips says that because she applied for the columnist job without notifying her sister first, it created bad feelings between them for many years. Each wrote her own advice column, and as competing columnists, they sometimes clashed; in 1956, Phillips offered her column to the Sioux City Journal at a reduced price, provided the paper refused to print her sister's column. The sisters ostensibly reconciled in 1964, but remained competitors. In 1958, after only two years writing their columns, they became "the most widely read and most quoted women in the world," according to Life magazine.

From 1963 to 1975, Phillips also hosted a daily Dear Abby program on CBS Radio. TV anchorwoman Diane Sawyer calls her the "pioneering queen of salty advice".

From 1987 until her mother's retirement, her daughter Jeanne co-wrote the column. In 2002, when Phillips' Alzheimer's disease made it impossible for her to continue writing, Jeanne assumed all the writing responsibilities of Dear Abby. After the family's announcement of Pauline's illness, Jeanne assumed the pen name Abigail Van Buren.

Phillips was considered liberal minded politically, yet personally conservative. She remained reluctant to advise unmarried couples to live together, for instance, until the 1990s, yet she adapted readily to social changes. One example:

Phillips died on January 16, 2013, at the age of 94, after having battled Alzheimer's disease for 11 years. She was survived by her husband of 73 years, Morton Phillips, daughter Jeanne Phillips, four grandchildren, and two great-grandchildren. Her son, Edward, died in 2011 at the age of 66.

As part of their work both sisters engaged with other editors, publishers, and the general public whenever they could. "Neither ever forgets a name," and they were uninhibited public speakers: they "whirl around the country appearing on radio and television and—dressed like visiting movie actresses—holding thousands of housewives spellbound in speeches at theaters and auditoriums."

In her July 8, 2017 Dear Abby column, Jeanne Phillips said her mother liked being a twin while her aunt wanted to be an individual, and this caused conflict between them.

She went by the pen name Abigail Van Buren, after the Old Testament prophetess from the Book of Samuel: Then David said to Abigail ... ‘Blessed is your advice and blessed are you. "Van Buren" was used after the President, Martin Van Buren.