Two Chinese mothers are among the world's eight billionaire mothers who built their fortunes on their own, the latest Forbes rich list showed.

Zhang Xin, CEO of Chinese property giant SOHO China, and Zhang Yin, head of paper processor Nine Dragons Paper, made the list compiled by Forbes.com, which announced 70 of the richest mothers in the world days before Mother's Day, which fell on Sunday.

Of the 70 billionaire mums, only eight built their business empires on their own, the list showed.

Along with JK Rowling, the author of the Harry Potter books, 45-year-old Zhang Xin and 53-year-old Zhang Yin proved to the world that having children is no barrier to making a billion dollars on their own.

Zhang Xin said she loves her work, but her favorite role is that of a protective "mother hen" to her two sons.

"The birth of my children has changed me and helped my career. I spend most of my evenings and weekends with them," she said on China's website SOHO.

Zhang Yin said she has dinner with her two children only once a week, but their understanding is the reason behind her success.

"I should have spent more time with my children. I went back to work when my younger son was only 1 month old, as a mother I owe him far too much," she said in an earlier interview.

Still, many Chinese readers said Mother's Day should be a day for all mothers to celebrate motherhood and it has nothing to do with wealth or status.

The event originated in the United States, but many Chinese people said love for mothers is in line with traditional Chinese respect for the elderly, as well as filial piety.

To that effect, many florists said Sunday saw the usual brisk sales for carnations, a Mother's Day essential in China.

There were worries that flower prices might go up this year because of a severe drought in Yunnan province, the country's major flower supplier, but few shops in Shanghai alone reported price hikes on Sunday.

Most florists said wholesale prices did rise, but they curbed retail prices to keep them in line with previous years' sales.

Until noon on Sunday, only one bunch of carnations priced at 200 yuan was left in the Shanghai FA Flower Studio, a popular flower shop located in central Shanghai.

The shop owner said the prices for carnations were little affected this year. Only varieties such as dianthus, which grows best in Yunnan, saw fluctuations in prices due to the recent drought.