Park, a 61-year-old newspaper executive, gets a different reaction today.
"When I tell people I have three sons and no daughter, they say they are sorry for my misfortune," she says. "Within a generation, I have turned from the luckiest woman possible to a pitiful mother."
In South Korea, once one of Asia's most rigidly patriarchal societies, a centuries-old preference for baby boys is fast receding. And that has led to what appears to be a decrease in the number of abortions performed after ultrasound testing reveals that a fetus is female.
According to a recent study by the World Bank, South Korea is the first of several Asian countries with large sex imbalances at birth to reverse the trend and move toward greater parity between the sexes. Currently, the ratio is about 108 boys born for every 100 girls, still above what is considered normal, but down from a peak of more than 116 boys born for every 100 girls in 1990.
The most important factor in changing attitudes toward girls was the radical shift in South Korea's economy that opened the doors to women in the workforce as never before. This has dismantled long-held traditions, which so devalued daughters that mothers would often apologize for giving birth to a girl.
The government also played a small role starting in the 1970s. Alarmed by the rise in sex-preference abortions, officials launched campaigns to change people's attitudes. One featured the popular Korean slogan, "One daughter raised well is worth 10 sons!"
In 1987, the government banned doctors from revealing the sex of a fetus before birth. But experts say enforcement has been lax.
Demographers hope that sex imbalances will begin to shrink in other rapidly developing Asian countries, notably China and India, where the same combination of a traditional preference for boys and ultrasound technology has led to a shortage of girls.
In China, the ratio is currently 111 boys born for every 100 girls, according to Central Intelligence Agency data. The current ratio for India is 112 boys for every 100 girls.
The United Nations Population Fund warns that rampant tinkering with nature's probabilities could lead to increased sexual violence and trafficking of women, as a generation of men finds its marriage prospects limited.
In South Korea, the imbalance has been closing steadily since 2002. The centuries-old preference for boys was rooted in an agrarian society that relied on sons to work on family farms. Another factor is that in Asia's Confucian societies, men were accorded special status because they were considered the carriers of the family's all-important bloodline.
Once the eldest son married, he and his wife went to live with his family; he was expected to support his parents financially while his wife was expected to care for them in their old age.
"In the old days, when there was no adequate social safety net, Korean parents regarded having a son as kind of making an investment for old-age security," says Chung Woo-jin, a professor at Yonsei University in Seoul.
Korean men felt asha-med if they had no sons; some divorced their wives if they did not bear boys.
Then in the 1970s and 1980s, the country's industrial revolution began to remake society.
Sons started taking higher-paying jobs in the cities, leaving their parents behind. And older Koreans found their own incomes rising, allowing them to save money for retirement. Married daughters were able to help their own elderly parents.
With the economy heating up, men could no longer afford to keep women out of the workforce, and women began to gain more confidence and respect.
Six of 10 South Korean women entered college in 2006; fewer than one out of 10 did so in 1981. In the National Assembly, women now hold about 13 percent of the seats, about double the percentage four years ago.
And a 2006 study by the Korea Institute for Health and Social Affairs showed that of 5,400 married South Korean women under 45 who were surveyed, only 10 percent said they felt that they must have a sondown from 40 percent in 1991.
"My husband and I have no preference at all for boys," says Park Su-mi, 29, a newlywed.
"We don't care whether we have a boy or girl because we don't see any difference between a boy and a girl in helping make our family happy."